You are sure right!

But neither Pe nor Joe mentioned the HORRORS of that swaged screw fatiguing the shaft through removal and reinstallation.... ON SOME WALBROS this is a death sentence. There are threads to be found where adjusting that plate by removal of the screw has resulted in the purchase of a new engine (or at least the payment for an extensively-repaired and internally-severely-damaged USED engine).

Some of the Walbro shafts don't have enough meat to tolerate that screw coming and going, particularly if the threads exposed on the initial install were swaged like most of them are. Removing that screw strips out a LOT of the meat of the shaft hole and weakens it severely, which also forces one to rely overly-much on the holding strength of retaining compound or Loctite.

I know I'll take some shots for bringing this up, as it sounds like you have a good solution to re-adjusting that plate. But in all good conscience, I couldn't read of your repair without telling the tale of the ingested carb-butterfly-screw.

NO criticism to either Pe or JoeAP, they both know a lot, and are good guys..... sometimes I just have to be "Chicken Little"....