I don't know for sure, but i do know rad hardened electronics are a lot more expensive. Older gear with bigger gates, slower clocks, all that stuff is more tolerant of a stray cosmic ray. which you'll get all the time in space. in a microsatellite, not much room for shielding. so i'd bet they just have to be really stingy.

My space engineering professor says for what he does (microsatellites mostly, but some science instruments for bigger satillites) they use off the shelf non-radiation hardened parts mostly, and get their reliability though software and hardware redundancy.

Rad hardened is only for GEO or long term missions. If you're throwing cube sats, or other micro (maybe even a small) sats, you're going to use off the shelf hardware. If you're worried, throw a little polyethylene around it. First few mm are going to do the majority of shielding. But at these low altitudes you're not going to get many bit flips and semiconductor damage isn't a concern because the low lifespan of the satellite. For the little errors you get, you can always reupload software, which you check on large or small satellites.