Gary
I have a roth clone that I got back in 2002 that until two years ago never got more than about 35cm leaf span. It would add new growths, loose growths. Maybe max out at 5 growths and then drop back down to 2 or so, and never bloom.
2 years ago I split the two remaining growths into baskets and started low K. One of the divisions has done nothing, but the other is now up to 6+ growths with a leaf span exceeding 60cm on the oldest growth. It also has a flower sheath slowly coming up!!
At least in this case culture is trumping genetics, but for 8 years I was convinced I had a genetically "compact clone".
I also had a reverse case with an adult roth with normal sized growths (obtained in 2005/2006) bloomed with 25-27cm flowers. It went into a growth frenzy, but then started producing smaller and smaller new growths and then problems with roots loss/erwinia rots. It bloomed its 2nd ( and last time) in 2009 or 2010, with cute little 11 cm flowers. Then the last few gowths promptly rotted. During that ownership period there was no shortage of repottings, pH adjustments, and potting mix schemes.
Just another couple of anecdotal observations that led to low K (and general starvation rations) programn I'm using now.:wink: