Trying to post again. This forum software doesn't seem to like me, but it is completely mutual. Should this end up as a bunch of posts, apologies.
After getting some proper router bits to replace the cheap sets I have been playing with so far, I note that they will not fit with the OF 1400 rotating chip catcher. Festool could have solved this with a deeper catcher but since they don't have one, I chose to modify the existing one instead.
Some pvc tube that is just about the right diameter.
I'll make a cutout in the outer pipe,
cut away the bottom of the catcher
and fit two inner pipes to get an adjustable aperture. This way we can route with a very small opening,
a wider opening,
and/or a taller opening.
This is a very rough prototype. If it works well but I find things that could be improved, I might build a nicer one.