I do have at least one daylily that I think meets the description of fast multiplier that produces many scapes and many blooms over a long period of time, and it seems to rebloom in a succession of cycles. 'Filled With Joy' Registered as 10-15 buds and three way branching.I lament the fact that scapes produced in a season is not something listed with registration info along with bud count and branching. But, I have tried to keep stats myself and have found it to me much more laborious than suspected.
First bloom this year was 04-19-19, I think it had blooms every month until mid September, but it is a fast multiplier so I had several clumps scattered about and that makes for a prolonged blooming period. I cut back on the clumps with the club plant sale this year.
I expect all my daylilies to rebloom, if they don't they will be some of the first on my cull list...if I can actually keep stats well enough to notice it. Yes, daylilies like "Filled With Joy' definitely would be considered right up there with the others that have high bud and branch counts, it is one of my current favorites.