I start a group of seeds in late spring to make clones for the once a year back deck pollen chuck in the fall. Otherwise, as you say, pop'em, grow 'em, and move on. I grok the benefits of 'keepers', but I'm invested big in seeds and want to see what's in them. I get a few disappointments, several winners, and mostly in between on the high side. But I'm a variety guy. I like the cabinet to have many jars of many flavors.
For instance, I've got eleven 10 day old seedlings just underway. One each of [Cannarado] Pucker Tang, [Bodhi} Black Raspberry, Space Monkey, [GPS] Pioneer Kush, California Cannon, [BOG] Sweet Cindy, [Irie] Cookies and Creme x Arise freebie, [Cosa Pharms] Groot Fruit freebie, [IHG] Black Nitro, Crypt Keeper, and {TGA] Ripped Bubba. I only need 4 shirleys, but can handle 5 if I get 'em. Any more, and the prettiest girls move on to make buds. That's my typical MO.