The local ECUTEK tuner can return your ECU back to stock map
Once that's done, its unlocked and it will no longer have the ecutek tune and you are free to do with whatever you want

i can understand why mms did what they did
ecutek came along before opensource ecu tuning became widely available to joe public
please it was also their way of protecting IP - which is based on their "research", dyno time, etc

rightly or wrongly, its their brand or product and they can do whatever they want