I had the idea to house rule druids wild shape to be proficiency bonus per rest, instead of 2 per rest until lv 20. Would this be overpowered?

(I Just looked up Short rest rules, and according to the PHB, there's no limit to how many Short rests that can be had per day, so If it's more than one, it probably would, but l want to get feedback on this idea, so l can 100% confirm if it's a dumb idea or not.)

LVs 1-4 2 per rest, same as RAW. 5-8 3 per rest, 9-12 4 per rest, 13-16 5 per rest. 17-19 6 per rest. (20=oo)

So, is a extra wild shape every few levels over powered? (I think so, but want to confirm) And if so, would granting a extra one or 2 at spesific levels (+1 at levels 5 and 13, for example, for a max of 4 per rest, before 20 level.)

I think it would be a bit strong, mainly because Moon Druid.

Folks gotta remember, the Druid is always a full caster first and foremost. Everything they get from their Wildshape is icing on the cake. More Wildshapes would also make the newer Druid subclasses more powerful (ie. Spores, Wildfire, Stars), especially since they get all of their Wildshapes back on a Short or Long rest.

Yep, more than 2 shapes per short rest is a lot of additional HP, especially for lower levels.

Moon druids with elemental form will also be even worse.

Wildshape gets stronger as you level and peace cleric shows having something both get stronger and get more uses as you level up can very easily get op.

Pre tasha for non moon druids it might have been OK but now wild shape cam be used to get a familiar and wild fire and stars druids get combat uses for wildshape they would be able to easily double up on wildshape. For example a level 9 stars druid could go into starry form and have a familiar giving the rogue or crit Fisher advantage for 2 combats and then take a short rest to get them back.

If you want to do something along these lines give them a 3rd use at some point in tier 3. Prevents a second elemental but gives a noticeable icrease in power without going too far. Druids are strong enough so if you do this give everyone a similar boost.

One thing worth noting is that Wildshape already scales in other ways; namely the Challenge Rating of beast you can transform into, and the duration of the Wildshape (which scales with Druid level), so simply scaling the uses would definitely be too strong.

That said, it's not the smoothest scaling, since the really good boosts don't come until 18th- (Wildshaped casting) and 20th-level (unlimited Wildshapes, no vocal or somatic components), and for non Circle of the Moon Druids the Wildshape forms aren't that strong.

So I can definitely see a desire to change the scaling a bit. There is currently a big trend on races especially to swap formerly short rest abilities to proficiency uses per long rest abilities, as this gives players a lot more control over them, so I'd maybe look at something along these lines.

For example, ditch the duration scaling (i.e- Wildshape only ever lasts one hour per use), and change it to double proficiency uses per long rest. So you would start off with four uses per long rest, scaling all the way up to twelve uses at 17th-level. Maybe during one of the Wild Shape Improvements (perhaps 8th?), I'd also add the ability to spend one use of Wildshape as an action while already Wildshaped in order to fully heal and extend the duration of your current form, without having to switch back into your normal form first. So this would allow you to spend 12 hours continuously Wildshaped. Archdruid would be changed to remove the duration limit on being Wildshaped, so you could spend as long as you want in a form, but you'd still need to spend the charges to change/heal (otherwise it would be OP to allow unlimited free healing).

This would have some trade offs though, as the current form actually lasts longer (from 10th-level you can spend 10 hours Wildshaped using just the two basic uses) however the long rest form would give you more control over your wildshapes by no longer being dependent upon short rests, giving you the ability to "reset" a prolonged form (so you might actually manage to stay in it for longer).

Anyway that's going into pure Homebrew territory, and this thread already kind of feels like it should be Homebrew & House Rules.

TL;DR
Definitely overpowered to simply increase uses, but there are alternatives depending what problem it is you want to solve (presumably feeling starved for uses at higher levels)?

The other important note here is most of the new features that use proficiency bonus uses get that number per long rest, not short rest; so this post isn't really talking a bout a change that is in line with newer material.

Seems unnecessary. What problem are you trying to solve with this houserule?