Grantapher has released an unofficial fix on the official Github repo of ValheimPlus (look through recent pull requests and issues) and someone also released ValheimPlus Fix on Nexus. Make sure to take regular backups of your characters and worlds if you plan on adding/removing mods.

From what we know, the ValheimPlus official dev is alive, he's just ignoring the community as a whole and taking Patreon's money. He did not even make a statement and his last activity was in december 2022...

I've just released a compiled version of the fix along with the Eitr Refinery and Wisp Spawner configuration added to Valheim Plus, allowing to tweak them in the configuration file: https://github.com/JF10R/ValheimPlus/releases/tag/0.9.9.13

Hello. Valheim plus has been corrected. It's name is "Valheim Plus Fix".
For most mods, you have to install Bepinex first.

yeah..if you already are deep in to the game with you char and the world it is good to be careful not to somehow ruin your playthru.. but in my exp. mods like this are safe, in worst case they will just not work anymore, problematic ones are those that change your inventory
and if not updated can lead to "broken save" lost of goods..
Mods like this (here is another one "Floors are Roofs") that you talk about is easy to test,
install the mod make a new char and test it in a new world..your main save will be safe.