There's nothing wrong with speed-running. But you must adapt your toolset to theirs. Meet their challenge.
First tool: Can't catch up with them? Roadblock them. - Ambushers blocked the road with trees - Landslide took the path up, now the PCs must climb, or make their way through a thick forest - Thick forest is very Tenser-disk-unfriendly, and uneven terrain might be a challenge for the steed - Mix and match watery terrain, bogs, rivers - Non-hostile fey creatures might go berzerk because of the unnatural steed. - Unnatural hazards like phantasmagorical spores or illusory terrain, mystique locale, etc. - Getting lost. - Their destination isn't where it was supposed to be ("Guys! Alderaan's gone!")
Even if you don't use the same trick twice, you'll challenge them in new and exciting way. At the end of the day, they might still circumvent you, but it will be a legit win.
Second tool: The double-tap For this, you'll have to actually have them in an encounter, so previous use of the roadblock will be necessary; unless you get them with a moving encounter Seems to me they rely a lot on utility magic to achieve this, and this is costly on spellslots. Hit them with subsequent encounters. Since they seems to evade it actively, throw them in quick two-encounters succession
- The first fight is just making time for the second wave - They were just stalling while the main villain tries to escape - It was a trap all along! - The characters get separated - Mayhem or hazard ensues and the players must escape from a plane trap / stone snare / landslide / surprise labyrinth.
Not all monsters want to fight. Look up some monsters that are too strong to be beaten but have time-shift or force teleport capabilities, like a Sphinx in his lair.
Third tool: dynamic dungeon
Are they storming the Temple of Evilzor to snatch the Rod of Infinite Wailing? Fine. But maybe, after the initial scouting, Lord Bloodstorm took back the Rod to give a pep talk to his evil minions. So when they sneak in, the Rod isn't in its resting place, the monsters all woke up and none of them are in their initial place. There's a lot of activity, moving pieces, and they have to think fast. Try to keep a minimum of safe spaces so they don't have the luxury of waiting 6 hours for spell slots to regenerate.
Also don't forget, they can't take two long rest on the same day. If they want to, they will have to wait it out. Make them missions time-sensitives, and they will have to watch out for these spell slots.
There's nothing wrong with speed-running. But you must adapt your toolset to theirs. Meet their challenge.
First tool: Can't catch up with them? Roadblock them.
- Ambushers blocked the road with trees
- Landslide took the path up, now the PCs must climb, or make their way through a thick forest
- Thick forest is very Tenser-disk-unfriendly, and uneven terrain might be a challenge for the steed
- Mix and match watery terrain, bogs, rivers
- Non-hostile fey creatures might go berzerk because of the unnatural steed.
- Unnatural hazards like phantasmagorical spores or illusory terrain, mystique locale, etc.
- Getting lost.
- Their destination isn't where it was supposed to be ("Guys! Alderaan's gone!")
Even if you don't use the same trick twice, you'll challenge them in new and exciting way. At the end of the day, they might still circumvent you, but it will be a legit win.
Second tool: The double-tap
For this, you'll have to actually have them in an encounter, so previous use of the roadblock will be necessary; unless you get them with a moving encounter
Seems to me they rely a lot on utility magic to achieve this, and this is costly on spellslots. Hit them with subsequent encounters. Since they seems to evade it actively, throw them in quick two-encounters succession
- The first fight is just making time for the second wave
- They were just stalling while the main villain tries to escape
- It was a trap all along!
- The characters get separated
- Mayhem or hazard ensues and the players must escape from a plane trap / stone snare / landslide / surprise labyrinth.
Not all monsters want to fight. Look up some monsters that are too strong to be beaten but have time-shift or force teleport capabilities, like a Sphinx in his lair.
Third tool: dynamic dungeon
Are they storming the Temple of Evilzor to snatch the Rod of Infinite Wailing? Fine. But maybe, after the initial scouting, Lord Bloodstorm took back the Rod to give a pep talk to his evil minions. So when they sneak in, the Rod isn't in its resting place, the monsters all woke up and none of them are in their initial place. There's a lot of activity, moving pieces, and they have to think fast. Try to keep a minimum of safe spaces so they don't have the luxury of waiting 6 hours for spell slots to regenerate.
Also don't forget, they can't take two long rest on the same day. If they want to, they will have to wait it out. Make them missions time-sensitives, and they will have to watch out for these spell slots.
Just make semi secret things