Dear Cameron,
IMVVHO, CFM does not matter if you have a well sealed vacuum system of the types suggested for EG. I do not think it matters if you take two minutes, or indeed, two hours to get to the the level of vacuum needed to "de-air" the glop, as long as the glop is not setting up in that period.
If there are worries about the epoxy out-gassing its chemical components, they will not appear until that critical level of vacuum is reached, and you can control that with a vacuum switch controlling the pump at any level you wish. Time, and vac pump though-put do not matter,unless the epoxy is going off.
Post#1478 and #1479. Aluminium preparation.
I could be wrong, but I'm reasonably sure that most epoxy manufacturers suggest mechanical abrasion ( it increases the surface area) and solvent de-greasing to improve the bond.
Best wishes
Martin