Brake type trigg hitch

Doesn't it have a reversing lock out tab?

You could but i think you will find that the thread isn't long enough.
A better way is to either buy the correct non braked coupling, have a spacer machined to put where the brake lockout thing is to remove all forward and aft movement. Or have the shaft shortened to the correct length so that there is little movement. I did the last option with mine and at the same time had bronze bushes made to fit into the body along with grease nipples. Twenty years later it is a good as new.
When you fit either the spacer or the shortened shaft you can remove the spring and stuff completely.