I know that some mods are not compatible with one another.

Generally speaking, is mod compatibility only an issue when you enable conflicting mods? Or does the mere face of installing them cause incompatibility, even if two conflicting mods are not enabled at the same time?

Thanks!

Installing conflicting mods shouldn't cause compatibility problems, unless they are enabled.

right, but I've experimented some strange issues when keeping old and new versions of the same mod in the mods folder.