In C&C: Tiberian Sun, the Tech Center, once built, could be sold with all additional building options it added remaining buildable. In RA2, this was removed for obvious reasons. However, I would like to request to give buildings (or anything else that might serve as Prereq in RP2) a "IsPermaPrerequiste=" (or "IsPermaNegativePrerequisite=") setting to restore this function if set to "yes". This would allow things like, say, having a facility that launches a RA-style Spy Sat and transforming into another structure upon firing the SW (if the "Transform upon SW fire" feature is put in). The transformation would ensure that the Spy Sat cannot be fired again from the same structure. However, if the structure is destroyed or sold, the player would be able to build a new one and launch the satellite again, which, because having no effect whatsoever, would be a gameplay debuff. However, if using IsPermaNegativePrerequiste=yes on the transformed structure and set NegativePrerequisite= on the original structure to the transformed structure, the player could not build it again, which would improve gameplay (IMO).
Of course, you could also use "IsPermaPrerequisite=yes/no" for both Prereq and NegPrereq, or use a setting PermaPrerequisite= / PermaNegativePrerequisite= on the buildable object itself rather than the object that serves as prereq...
The following solution has been posted before:
Add ammo = 1 to the SW building, so the SW can only be fired once.
this doesn't work now, because ammo = 1 tag doesn't work on buidlings.