MRT has been selling transponders for about 5 years to my knowledge with no compatibility problems.
MyLaps only did this to force a monopoly on us, and to continue with their ongoing planned obsolescence of their earlier products (including earlier decoders that worked just fine) to keep gouging the RC market - by introduce ing a new decoder and transponder that doesn't do anything (really) the old one didn't do.
Just like their discontinued support of handout transponders, which was done to increase revenue from the sale of personal teansponders - how long do you think you current transpondsr will be good, until their lastest software upgrade makes it obsolete as well?