So... These "Last Resort" Eevees...

Last Resort is booty, so don't evolve Eevee if you want their evolutions to have the best moves. Personally, I evolved to have 1 shiny of each current eeveelution with last resort and sent all the non-shinies (except the very best ones) to the professor.

From what i've heard, people over-speculated Last Resort's ability as a great neutral dps attacker, especially regarding Espeon. Now it's a pretty bad move in practice.

I'd rather wait till after the window has passed then i'll evolve my shinies with actual STAB charged moves.

I evolved my shinies now because they all have garbage IVs and will be nothing more than trophies anyway. I managed to get at least one of each current eevolution and put 3 aside for future ones. If IV boosting items are ever introduced, I might TM them at that point.

You could do what I do; seeing as LR isn't a *great* move on any of the Eeveelutions (meaning they all have movesets that are better), I evolved a bunch of high-level, middling-CP Eevees this weekend. This way I have 2-3 each of Jolteon, Vaporeon, and Flareon (some I'll transfer/trade away), and one each of Espeon and Umbreon, with LR. Saving my high-IV high-level Eevees for future evolutions, and if any of the existing ones get moveset changes.