I think it will likely be up to the genetics of the rosette and cause of the cresting. Some crests may be stable, some not. Some may not even be able to produce offsets. Since you do not know the age and since it looks old, you will have to make a decision. Do you physically divide it to propagate or do you wait and try for offsets, knowing it may bloom and die, losing the crested form?
If it was me, and I had some confidence that I could give it the care necessary to keep the pieces alive, I would divide it using the vertical division technique and some tlc. Once I had a couple of crested pieces going, I would then watch to see if any of them could produce offsets. I'd let some mature as long as it takes but continue to divide others (after recovery and growth, of course) to propagate the plant. I think you need some intervention to get past the "I only have just this one crested form" stage. Then when you have multiple plants, you could do some experimentation.
It's interesting to come back to the Fame Monstrose a bit. While this is not a crest, it is an unusual form. The original Fame Monstrose I have is now in its second generation of offsets. I don't know how old the original is that I have, but it has not bloomed so far. It has produced at least two generations of offsets. That's what makes them so interesting (the unusual ones) is that the rules may be different for each one.
