Hi,
you have in last time with 1.3.0 and now with 1.3.1 new thinks added to Minecrafts Mod Wavey Capes. I hope you can this add in 1.12.2 Version for Minecraft. I love it but i miss so features in 1.12.2

Right now 1.12.2/1.8.9 are not really a priority to update(see https://tr7zw.github.io/versions/ ).
I might get around to it eventually, but right now I'm just backporting 1.3.2 down to 1.16, and then switching over to other mods to update them to the new build system for 1.19-1.16, adding things like the tooltips.