There is a reason why plugins were disabled on the new ^3.040 versions 
It uses a new Nodejs version which means all native node modules need to be rebuilt. So plugin devs need to rebuild the plugin for this new Node version and then make a new pluign.zip
If you want to manually install plugins still on the new Buster betas, you will need a figure out all the build dependencies of the plugin and rebuild them.
tl;dr
Ensure you have gcc/g++ compilers installed and then run
cd /data/xxx/yyy/plugin
mv ./node_modules ./node_modules_v8
npm install --no-package-lock --only=production