How about either once a week/month, or maybe always on a base that can be raided, the raiders have a chance to get a "Mysterious Crate" (lame name i know) rather than a normal base crate. These Mysterious Crates would have random effects similar to the effect of the Service Terminal base module, however would last different lengths of time depending on the level of the base it was taken from (maybe 2 hours from a lvl3 base, while 8 to 10 hours from a lvl7). Note that there would be 3 different possible effects in each Crate, but only one will be given to the player.

However on bases that are level 5 or higher, the "rare" option could be one of the Holiday Terminal effects or possibly new ones, but would need ideas on these.

Any Comments, feedback or changes to this?

Well, considering our group only targets bases that have a chance to drop enumeration crystals (level 5+), I'd really rather not have a temporary buff come in a crate.

Agreed. unless its something really good i dont want any less chance of getting crystals.