It lets us run without doing anything when Valorant first release. I tried with my partner. IDK about now seems you asked this question, I think they blocked it.

Valorant's Vanguard anticheat prevents 2nd or more mouse in the system to stop working
once one instance of the game is launched and working.
Any additional instance of Valorant run on system wont have mouse working even though keyboard still works.

Valorant utilizes a robust anti-cheat system (Vanguard) that might detect attempts to run multiple instances as suspicious activity, potentially leading to a ban

Running multiple instances of Valorant simultaneously on a single PC using a multi-seat configuration like Aster can be challenging due to the game's anti-cheat system and its restrictions on multiple instances.