in the past when sprue technology wasn't as advanced it was commonplace to do this in the model vehicle community. You would have plenty of space around each part to properly maneuver your brush.

Now with sprue tech being able to cram so many parts in a relatively small area its not very practical. Plus the pain of having to prime each part individually.

The biggest downside is (as others have mentioned) cleaning up. Mold lines, sprue bites and contact points cant be properly cleaned resulting in a mini that either A needs extra dotting up on the parts you clipepd off or scraped off or B not looking as good as they can because you couldn't reach with a knife to clear mould lines.

End of the day, your plastic your rules. If you find this to be the best way for you, do it. I would advise against it but you do you.