Last season Q&A 990 ( https://www.robotevents.com/VEXU/2021-2022/QA/990 ) was asked but never answered regarding the legality of driving non-vex solenoids. This question is similar to that question.
VUR10b states:
Sensors and electronics CANNOT directly electrically interface with VEX motors or solenoids.
There are 2 ways that VUR10b can be interpreted. Either, it applies to “VEX (motors or solenoids)” or it applies to “ (VEX motors) or (solenoids)” The former interpretation would allow custom electronics to interface directly with non-vex solenoids. This would be useful, as most commercially available solenoids do not function of of the 5v provided by the V5 brain, and instead require 12v power which can be provided by custom electronics. If this is not legal, then it is not possible to use most commercial solenoids.
Historically, the GDC has ruled this to be legal, as it did in Q&A 93:
https://www.robotevents.com/VRC/2018-2019/QA/93
Is it still legal to power commercial solenoids using custom electronics?