[snblg]

Those installed by make install. Likewise you build, then install the addon. Normal unix software deployment. No idea what zip file you refer to

I refer to your zip : https://github.com/notspiff/audiodecoder.timidity

I have not installed the dev kodi software
Because I want to keep official stable Krypton version.

It's not hard to : yaourt -S kodi-devel-audiodecoder-timidity
does the job
Compiling it is quite long (several minutes). And at the end, I answer No, to keep my krypton version.

I suppose I have to wait for an upgrade of this addon.
My wife will use it a lot !