Quad King
I believe that the process of heat cycling, is to allow the rings to settle into the fresh cross hatching in the bore by the process of expansion and contraction, without putting the components to excess strain.
As an example the more pressure you exert to the piston crown the more blow by you will produce at the ring lands. It is the pressure that then gets in behind the rings that causes them to expand toward the cylinder walls.
The more they expand towards the cylinder walls, the more they will bite into the crosshatching, therefore causing the rings to grab harder into the cylinder, which can cause problems as they are being gripped by a fresh crosshatching.
If you do the heat cycling, the rings will now be nearly bedded in, ready for the gentle riding which will finish the break in process.
As to the damage, if any, that may have been caused I cannot comment on as some people fang a fresh rebuild from the start and state that they have had no problems.
If it were me I would re tension the head and jug and then ride a tank of gas through at no more than 3/4 throttle, and then let it rip.