Alex, do you think something similar to this would work?

A few years ago when I attached my Bosch jigsaw upside down to a board I was going to make something like this. I found out quickly that you must hold the board down, and you can't let your mind wander for even a second or you'll have a problem. I was using mine to cut metal.

I was going to make this out of aluminum because I have a tig welder. With thicker material it could be pinned instead, or I suppose it could be made of steel also if you have the means.

There is no adjustment for different thicknesses, but I didn’t think that far ahead because I was going to use it on sheet metal less than 3mm.

I had forgotten all about it until your post.

Bruce, my Bosch is not expensive and I think it's as good as most could hope for, it is an excellent tool.

.................. John D....................