They're in the Personal list now, and I've seen them fairly often in the Earth locations and the Federation sectors. I think they might also show up from the Operations Officer, but I don't remember for sure.
There is something wonky somewhere... I rarely see a BOFF assignment on my Fed characters now and I have never seen a Saurian. But all my Klingons have a full complement of efficient Letheans some with rank 3 rare abilities and BOFF assignments pop up every day.
Is it me or do doff system bugs seem a bit feast or famine, like with the cultural exchanges before the fix.
**defiantly wonky today I've seen no FED boff assingments but right now on my Orion I have four, three of those are Lethean...