At least they told you it wouldn't work well. If you went by the specs on the box and advertising you would have bought it and been very unhappy. I have been complaining to RF/KE for years about their misleading hardware requirements. Alas to no avail. Glad you got a correct answer from them. G4/4.5/5 have problems with lots of hardware, video cards being the biggest problem.
Realflight requires a high end gaming computer to work and look decent. BTDT [:@]