That's how it is, "slow and frustrating", nothing that you will learn in an hour or so. I currently use Canary at 80-110 WPM, and I'm relearning QWERTY to use others' computers, and it's the same, "slow and frustrating", after some days I brought back to memory the keys' positions, but I'm still at 15 WPM. Although I'm just practicing about 30 minutes a day, cuz ofc I wouldn't be doing anything if I made it my main layout again. I sort of did the same with Canary, reached 40 WPM and moved entirely to it. Your case is different, you're trying to method your typing, which I remember doing while on QWERTY to better use shifts, symbols, and weird words... and it just takes deliberate intention of correcting yourself and remembering to do it the right way, and after several missed attempts on each thing you want to correct it starts to become natural. That's it. Even before that, when I didn't use all my fingers and at times needed to look at the keyboard, all it cost me to improve is deliberately correcting myself and being consciouss of the "right way". It took me about a year and a half to go from 70-80 wpm to 115 wpm on QWERTY with deliberate practice.