I've read of Dremmel bearing runout a number of times on luthier type forums. Maybe I just got a good one as it has zero runout . I've never had a problem with it. It has cut binding/purfling ledges, rosettes, saddle slots , inlays and many other tasks. Never any gaps . Being an incredibly fussy builder when it comes to tolerances , I wouldn't use it if isn't wasn't up to the task . I own a Makita Laminate trimmer ,but for me , it's just too bulky on some jobs.
There are a number of jigs I've built for my Dremmel which have proved successful .Here's a link to my binding jig
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Hip , I have one of those units , and whilst it doesn't have the precision of my Dremmel , is handy for things like little buffing jobs and the like