I understand your method, BUT, when you work from Lightroom and edit in an external editor (X-Transformer) doesn't Lightroom only give you the option to edit with Lightroom adjustments? Even though you've made no adjustments in Lightroom, wouldn't Lightroom automatically apply the default 25% sharpening that it automatically gives to RAW (RAF) files before it's sent to X-Transformer?
I'm away from my computer and can't check right now.
I'll try your settings soon though!