I know I am bit late here. What exactly do you mean by spell triggers? The only spells I know of that work off of Triggers are Contingency and Glyph of Warding. So if you could elaborate on that part a bit more that would be wonderful oh and Wizard gets those spells the Sorcerer does not.

Hey, just wanted to say that I've updated a new version of my Wizard companion to this subclass here:
[https://www.dndbeyond.com/subclasses/522102-chronomancer]

The comments of that subclass include links to 50+ Chronomancer spells of all levels that I've set to be compatible with both my Wizard Chronomancer, and with this Sorcerer Chronomancer.

All the stuff said by DanHarrisSeraph is very valid and I agree with almost all of it. I find with a lot of these homebrewed subclasses, that they are often very OP. I've done it plenty of times myself. My feedback for this is:

• For the haste and slow spells. Have the sorcery point cost equal the spells level based on the flexible casting table. 3 is still a very low cost and should be at least 5 points to cast. Though I like the idea of just adding the spells to your list of spells but does not contribute to your known spells maximum much better.
• Rewind time, cool concept but lacks practicality and manageability. A simpler version might be "Freeze time". Basically 1-2 free uses of the Hold person spell. There are plenty of spells or class effects that you could look into an draw from.
• Restraining Spell is a super cool idea and I really like where it is going but the description is very vague and the actual effects are unclear. Based on the SP cost and what you've done so far I would reword it to something along the lines of "After a successful spell attack, as a bonus action, spend 3 sorcery points to attempt to trap the creature within their own timeline. The affected creature must make a Constitution (could be Dex or whatever) saving throw or be incapacitated and have their movement reduced to 0. At the end of each of the creature's turns it can make a Constitution saving throw in an attempt to break free."
• Not a fan of Timelessness. Seems like a free unnecessary power boost where it definitely shouldn't be given. I like the idea of being able to maybe cast Disguise Self for free in a similar way to Furbolgs but maybe it is restricted to different possible versions of yourself that actually have physical form. Anywhere from early childhood to late seniority and maybe even allow gender swapping but all of these forms are reminiscent of what your character looks like (same wart on the nose, same bright blue hair, etc.). The whole health cap increase feels cheap and seems like you're trying to get free buffs which is not "healthy" for a game (sorry for the pun :-P).
• Duality seems pretty dope. I quite like it and would only suggest a few tweaks. First maybe limit the casting of it to 1 per long rest instead of costing SP. This spell essentially gives you a free action per turn as well as a free meat shield. You could also remove the meat shield part and instead maybe even make it a potential risk. Something along the lines of: "Any damage taken by the duplicate is also taken by the caster. If the caster and duplicate suffer damage from the same spell, attack or ability then both the caster and the duplicate take the damage from the highest source (if the caster only takes half damage but the duplicate takes full damage then both the caster and the duplicate take full damage). As a bonus action, the caster can dispel the duplicate. If either the caster or the duplicate reach 0 health, the duplicate vanishes and the caster is instead reduced to 1 health." Considering your calling a version of yourself from another reality it isn't entirely surprising to share a health pool or at least take some damage.

Hi! Absolutely love this subclass for sorcerer, and I find that all the archetype options are very fitting and flavorful, but there are a few iffy things that would personally keep me from playing this or allowing this in one of my own games.

• Firstly, the 6th level ability to cast the spells Haste and Slow using sorcery points, while awesome and very reminiscent of the Shadow Sorcerer's ability to do the same with the Darkness spell, seems a bit more powerful. Both spells are known to be extremely potent, as most 3rd level spells are, and being able to cast them using only that number of sorcery points gives your Chronomancer an extreme buff. I would recommend that the ability adds the two spells to the sorcerer's known spells, if they didn't know them already, and makes it so they don't count for the number of spells known. This allows them to cast the spells using their spell slots or sorcery points. Additionally, I would increase the sorcery point cost to cast them at least to 3 sorcery points to match the natural level of the spell.
• Second, regarding the 14th level Rewind Time ability. This, flavor wise, sounds amazing! But in game, making anything retake their last turn can be extremely confusing. Combat is chaotic, and both the players and the DM are prone to forgetting what happened in past turns. The ability is a fun thought, but unless the Chronomancer player is willing to keep track of what happens on every single turn that played out since the last round, it can be an extreme hassle. Perhaps a reactionary ability that allows the Chronomancer to Give or Take Time from other creatures. Following an allied creature's turn, or before an enemy creature's turn you can use your reaction to give your ally an additional turn, or to skip the enemy's turn. The enemy must make a Constitution/Wisdom/Charisma saving throw (Depending on whether you want it to battle the time-lock with its physical prowess or its force of will or personality), and for either effect you give up your own next turn. This, I believe, makes for a much more manageable ability while still being very potent and flavorful. While it doesn't give you any of the damage mitigation that rewinding effects and wounds and positions could, being able to give your Fighter, Barbarian, or Paladin an extra turn, or being able to steal the turn of a big bad at the cost of your own (flavored as keeping them locked in time with all of your focus and concentration), can still be a great boon to your party, in my opinion anyway.