.005 grc = 5 sat, plus a donation really isnt hurting, and as stated yes on a pool you crunch for the owner instead of solo, but as you said 1690 balance looks like a stake every 2 months +/- so a balance of at least 10k will be great, and also like i said this is just a visual experiment to share, crunching GRC is already at a profit loss unless you have really cheap electricity or free, its all for science.