I've only found two really good mods: Jacob1's mod and Alchemy mod.
The first one can be used as a replacement of the official TPT, it doesn't break saves, isn't outdated and includes a script manager to expand it even more (note: downloaded scripts can't be used on public saves). I use it more than the official TPT.
Download Jacob1's mod:
https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=11117
Alchemy mod can't be used as a replacement of the official TPT (breaks saves) but I find fun play with it; You start with only four elements: FIRE, WATR, OXYG and STNE and then you must create the other elements. Not exactly what you're looking for but isn't outdated and it's a good time-killer.
Download Alchemy mod:
https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=21011