It's also possible they just forgot to add some games with a lower revision to the internal table...
They didn't forget, they just didn't do it, since POPS hasn't been updated since pre 0x06070000. Any config 0x06070000 and up should work fine on PSP, but it looks like only 0x06070070+ will work on Vita.
However, Vita seems to have its own table with even more games in it, most likely all of the EBOOT configs we have found that are 0x06070070 and above, and maybe even more. I have tested Metal Gear Solid: Integral JP's official EBOOT and custom pop-fe EBOOT (with no config) and both work exactly the same. After putting a default/zeroed config in, audio glitches start happening in voice lines right away. If I were to guess correctly, a pop-fe conversion of this game will have audio glitches on PSP. Maybe if you have some time, you could test this.
And if this is true, we probably messed up with porting EVERYTHING over to Vita, lol. Mostly me, with the big chunk of configs, but we don't really know until we see the Vita's internal table. If true, even changing version to 0x06070060 should make all the current EBOOT configs we extracted PSP-only.
Let me test Rockman Dash and see if it works fine without any config on Vita. I think that will also be a good test to see how things are playing out.
EDIT: Just tested digest-ban pop-fe conversion with empty config: boss works perfect. So, I think that means all 0x06070060 and below configs have been added in for Vita! I would assume Vita also has the Spyro and Armored Core configs in its table as well, but...no idea until we see that table!