What I’ve learned is squeeze the handles together (after looking that the blades don’t hit the anvil and then once I know I’m ok I put a rubber hand over the handles so the tool is completely locked and I adjust the anvil and the two blades until I see nothing can get any better and I tighten it all up good.
Keep a wrench and a screwdriver on your you when you go to the field for grafting.
Dax