Thread: Wood screw for leg vise - will acetal bushing help to prevent racking?

Back in 2012, Derek Cohen observed that his wooden-thread Roubo-style leg vise was slightly racking.

This was back in the thread: Leg vise Parallel Guide Adjuster by Ancora Yacht Service

He put it down to the need for tighter alignment of the parallel guide (the thin tongue that travels through the leg) at the base of the leg chop. To fix the problem, he attached a guide channel for the guide to slide in.

I've noticed that Benchcrafted, in their installation instructions for their Crisscross guides, put a bushing made of acetal around the vise screw on the front of the bench leg, that they say is to "stabilize the
lateral movement of the vise screw". They say that "The bushing is milled to be just a few thousandths larger than the screw's width, thereby guaranteeing good guidance for the screw and thus smooth in-out travel of the chop". Basically it is a plate of acetal about 8 to 10 mm thick, with a hole for the screw bored through it.

There is also a bit more about their acetal bushing, on their blog post Glide Crisscross Acetal Bushing--Modification

Probably for a big wooden screw with thread pitch about 2 tpi, the acetal ought to be about 12 to 20 mm thick to bridge the threads adequately.

What do others think, would addition of an acetal bushing help to prevent racking of the vise chop when using a wooden vise screw, such as the Lake Erie Toolworks 64mm dia wood screw?

Looks like small pieces of acetal (delrin) sheet can be got on eBay, so supply is ok.