"In Place" Flush Trimming?

[Peter Rossi]

Background:

My wife and I are making a basic "bookcase-style" dollhouse for our daughter's third birthday.

Last night, after our jigsaw died, I borrowed one and cut out the backing (1/4" plywood).  I'm wondering if there's any reason not to run a flush trim bit with a pilot bearing around said backing after just clamping it to the dollhouse itself, as opposed to making a template and trimming to size that way.Particularly because it seems like a roughly 3' square template that's going to be used exactly ONCE would be a waste.

Common sense says it's perfectly acceptable as long as I'm willing to take the risk of screwing up, but my common sense and "common" common sense frequently don't align, so I thought I'd ask.

[John Schaben]

No reason at all I can think of. That's a perfect application for one of those small trim routers but any will work. If you have any small convolutions around it you will need to stick with a fairly small diameter flush trim.

[Peter Rossi]

Thanks John, that's exactly what I figured, but it's always nice to have independent confirmation.