The workaround will be very complicated so if anyone has an idea of how to "activate" it, I will be grateful.
I tried to combine with arithmetic operations just to include this User value, no luck.
I tried to use it as a selector between two Constant inputs so the output will be a numeric parameter, no luck.
I tried to set it like some value on Null+Trasform operator and all that connected to Marker input (Z fixed size and the exported back as Z Attribute), no luck.