Hey Dave - -
initially, I was flying, and could hear the engine change RPM's very slightly. Next landing, when I turned off 1 mag, the engine stopped. Not sure how smart it was, but I flew it home. Other one failed at home airport before take-off. Found while doing mag-check. I have been reluctant to mention this because of the very negative thoughts it might bring up, but that may have been wrong also.
IF I SAY NOTHING ELSE - DO NOT BUY ONE NEW MODULE. ROTAX HAS A 'SPECIAL' PROGRAM WHERE YOU CAN BUY A PAIR with soft-start, FOR LESS THAN (1) NEW USED TO COST. Says a lot to me, but anyway, don't buy 1 new one. YOU MAY HAVE TO ASK FOR THE SPECIAL PRICING !
I would also add, likely later engines with Soft-Start built in, will not have this problem.