Error while compiling HeliControl: The type 'System.Text.StringBuilder' cannot be used as type parameter 'T' in the generic type or method 'Pool.Free<T>(ref T)'. There is no implicit reference conversion from 'System.Text.StringBuilder' to 'Facepunch.Pool.IPooled'. | Line: 905, Pos: 38

Seems that this will never get fixed
https://umod.org/community/heli-control/54259-helicontrol

I have a fixed and working version of HeliControl but I don't know how to share it here without just posting the code for the plugin, but i don't think we're allowed to that.