Nice looking rides!
I am learning to "trust" the stock shifter more. I find the transmission/shifter combo works far better the less you man handle/force it. I have not had any recent lock outs, but and I am mostly shifting under 7000 rpm.
You have to swap the shifter and clutch. "Trusting" the stock stuff is no fun! I had an MGW shifter and Exedy Mach 500 clutch/flywheel in mine. Those mods made the car so much more enjoyable. They were amazing shifting at 8200!