The problem with much longer phrases in styles mostly boils down to the tendency to place little pickups in the middle, which is fine and dandy if your song is straightforward in structure, but can lead to some odd rhythms if for instance you have the odd shorter or longer phrase.

And, of course, if you DO trigger a fill, it goes back to the beginning of the Variation, where to be less repetitive, maybe sometimes it ought to drop into the middle..?

I’ve always felt that arrangers needed an extra set of fills, for ‘Fill-to-Same’ that were just little pickups from the main groove of the Variation allowing YOU to pick and choose where they come in.

In the meantime, if you DO want a much longer Variation with subtle changes, it’s usually a fairly simple edit to append a Variation to itself, and then get in there and just adjust the odd note or rhythm in the longer version. Just be cautious about putting something too specific at the four bar location. Not EVERY song has a simple structure!