Dave__67 wrote:

(...)

You don't need a guide, you need a damper.

2 rubber wheels sprung to close on the blade near the top mounted on
an arm that can move back and forth a bit, maybe have the whole arm
swing up and out of the way if you are working on pieces with a hole
that need to be placed down over the blade.

Yup. That is very similar to the BladeRunner
approach and it does seem to work well enough.
For a while.

--Winston