Yes I am.
It's possible that the action usually attributed to Lachenal was made/designed by Nickolds, It's also possible that Nickolds made/designed the slotted cylindrical post in the period that he worked for Wheatstone's before Lachenal started there. Nickolds also used another design that looked like a combination of the other two actions. I think that Case and Jones' riveted actions predated Wheatstone's action.
Chidley's action started in 1850 and is unique.
All systems will have flaws. It is a problem with not having a frictionless bearing. As you noted - straight levers are going to be more desirable as they will not cause issues with side wear on action posts, so - look for straight posts with axles supported on both sides. Not sure off hand who has made such an action!
Chris