State Machine and Conditions for Animations

AnimationTree State Machine is close to perfect option for me, unfortunately its Advance Conditions are very limited for me. I know Expressions exist in Godot 4 but I’m creating on Godot 3.5 for personal reasons.

*Problem
AnimationTree has limited Advance Condition.
AnimationTree Substates cannot use a single Condition so I needed to code all Conditions in Root State and each Substate Machine.

*Asking for Help
I want to use AnimationTree’s Animation State Machine because it helps with automation of Animation Transition, but I needed more than one Advance Conditions.
I also want these Advance Conditions to persist in all States and Substates instead of setting each Boolean to each States and Substates.
Is there an addon that allows the usage of a State Machine with AnimationPlayer Animations or is there a way for me to modify how Animation State Machine’s Advance Conditions works so that I can make my own State Conditions?