Dark_AleK only updates when there are significant features. Lately there's just been minor update (in his eyes) so he doesn't give a shit, even when the PSN Store blocks running newer games.
I installed the 5.50 GEN-B, or whatever, on my PSP-1001 and it's fine.
But the big issue with the later motherboards is that without kernel mode access, we can't write to the firmware, so the hacks are always temporary.