After talking it through with wetsuit we're thinking of doing something similar to how the Moon faucets used to work in that the longer you wait to roll the more you get.
You would get a display counting up from 0.01 Sats and you can only roll when it becomes greater than 1.00 Sats. If it was 2.63 and you rolled you would get 2 and the counter would start at 0.63 for the next roll.
The Free BTC bonus for Reward Points would make the timer go x% faster.
Sounds good, I definitely recall moonbitcoin and doge they all worked like this and actually made it perfect for those who can only remember to login once a day, and if you somehow forgot for a week,,, it rewards you with a big bonus.
Consecutive days bonus added to 100% IIRC.
But maybe the high rollers with a lot of freebtc would reject this idea?