Here is a photo of my set up with the Canon EOS R and Helicon Focus Tube, plus a few extras in-between.

No issues at all taking stacks of 50 frames so far (that's when took my finger off the shutter release).

Cheers

Dennis

I have had no issues with the Helicon Focus Tube and the following configuration with the Canon EF 180mm F3.5L:

Canon (EOS R) -> (Canon EF-RF Adapter) -> (Helicon FB Tube) -> (Canon EF 25mm Tube) -> (Canon Extender EF x1.4 Mk III) - (Canon 180mm F3.5L) lens.

The AF on the 180mm is a bit slow and ...