As the title says: Why is e.g. 靴を脱いだとしたら、家に入り下さい considered unnatural and 靴を脱ぎ終えたら、家に入り下さい is the more natural way of communicating “Please enter the home after you have finished taking off your shoes”
If all V[過去形]としたら are unnatural usage — what is the deeper grammtical reason for it being unnatural?
お入りください is a more respectful way to say 入ってください, but it needs the お.
I see — thanks for explaining. I think I somewhat get it now.