Hey Rob - no, you understood my intention perfectly.
That was one of my concerns (long-term wear), and I had a similar thought - use the washers to set the initial alignment, then remove them when everything is tightened up.
However my problem was that once everything was set you can't remove them. However, your idea of using slotted washers is an excellent one - I can have them in place, tighten them down to set the initial alignment, then remove them when done.
There is plenty of room - usually my final alingment is a nut + 3-4washers, so there'd be plenty of room to do as you're suggesting.
For anybody whose curious, this is what Rob is referring to - I am (?was?) using fender washers to serve as a door stop for the hinge.