But you do realize coding or not the only difference between developers using this add-on and not is the speed at which it takes to develop what they want, not to mention HUDs are clientside and this "prevention" is completely useless against someone who knows how to steal clientside code.
The HUD should be completely disconnected from your script once exported, and allow the developers who buy your add-on to use to help themselves work on external projects faster.
All you're doing is delaying, not halting, at the cost of more sales (Even from gmodstore add-on developers who want to get the clientside part over with) and their freedom with the add-on (if they don't want a stack of add-ons on their server with no use any-more).