This change reduces the time it takes from you do some work until it is fully paid. That's a good thing. Also, 10 shifts taking over 5 days has been a problem for newbies and for people who (wrongly) believe you have to work 10 shifts before getting proper pay. With the new setting it will happen more often that there is a shift without pay, but also shifts with very high pay. However, this doesn't change anything if you are mining in the pool 24/7, you earn the same anyway. It only creates short-term variance.

The size of the shifts is not really a big deal. If you have 1% of the pool hashrate then you get 1% of the payouts. That's not changing.

I'm mostly trying to find a balance between the wrong belief that "short shifts give me unfair low pay" and the wrong belief that "long shifts give me unfair low pay". So I don't have to explain things as often.