Why didn't Quaid keep the fat lady cover?

I wondered the same thing, but it seemed the "costume" was some sort of bio-mechanical apparatus that suffered a system failure of some kind. It didn't make sense that Quaid would intentionally abandon that guise until he was out of sight of the authorities.

I think that because it's a perfect disguise they had to have the "2 weeks" malfunction so that it would make sense to have Arnie back as Quaid in the lead role. I mean who wants to see an action movie starring that woman?