Would a crew xp gain history be possible?

[LameFox]

As slow as levelling is, and without any sort of notification, it's hard to even remember what someone's skill was to know if it changed. I'd basically have to write it down to know it happened at all in many cases.

What would happen if the game kept track of it? Would there be performance issues, given how many personnel a player can have, or is writing something so little just going to have negligible impact regardless?