Opacity with unredir-if-possible = true

[ScuroGuardiano]

Hello, is it possible to allow opacity for specified window even if full-screen window is active with unredir-if-possible = true? I have third party app that serves as an overlay for game I play. I had to add game to unredir-if-possible-exclude so overlay isn't big black rectangle but that decreases performance... Can compositor be only active for one specified window [overlay]?