Tried to change it by myself but my programming is a mess.
I came upon this, which seems to be the LUA for the original UI.
https://esoapi.uesp.net/100012/src/i...ebars.lua.html
There is a setting in line 338, "Shrunk width" which if changed might solve the problem of the OP. Donīt know how to turn that into an Addon.