This mod will activate all unlocked skills without the need to equip them.
Skills can still be equipped to benefit from Mutagen Linking as usual.

Existing saves should work immediately without the need to reset, equip or unequip skills to get them to work.

This mod is tagged (beta) because so far I have only tested it quickly with various passive or active skills in different but limited savegame conditions. So be mindful of that if you wish to use the mod.
It's just a mod I did for myself as I'm about to start a new game and want such feature. I decided to post it here if others may want the same thing.

To manually install the mod, just unzip the file into your "<main game directory>\mods\" folder.
To manually uninstall the mod , just delete the "modElysAllSkillsActive" folder inside your "<main game directory>\mods" folder.

Note: This mod will conflict with any mod modifying "scripts\game\gameplay\ability\PlayerAbilityManager.ws" file.