Partial success: JAC Vapour's Sarah Dyer sent me instructions on how to switch to wattage mode permanently, so the mod is now usable. I can still only adjust the wattage in .5W increments, though, so I've written her back asking if she has a fix for that (I guess she didn't notice my mention of that peculiarity in my first message). If she has no suggestions, I'll just hold onto the thing and use it as is. I'd prefer to be able to adjust .1W at a time, but it's not worth the trouble of sending the
device back to Scotland.
I'll report back on what happens next. It's gripping stuff, I know.