Verxion - While TextBlade makes it easier to type with 8 fingers, it’s not required to be productive.
Other users - long time 2 or 4 finger typists, have used those same fingers on TextBlade and it can still work fine for them.
If however, you want to advance to standard 8 finger touch type finger-to-letter assignments, TextBlade’s one-key-per-finger architecture does make it easier to learn classic 8 finger assignments.
Your 8 fingers cannot get lost with a dedicated key per finger, as compared to a 6 row sea of 75 staggered keys on a legacy laptop.
The test you did with the Apple Smart Keyboard cover, where your speed dropped from 80 to 18 wpm just by using 8 fingers instead of the 4, (no TextBlade) - this shows the dominant effect here. Moving to 8 finger typing vs. your improvised style is the bigger change to your muscle memory.
In general, when you want to measure the effect of any specific variable, you try to hold all others constant, measure the discrete effect, then move on to the next variable and measure its independent effect.
Here, there are two principal variables for you -
4 vs. 8 finger typing
TextBlade 8 key vs. 75 key legacy layout
Just like you benchmarked 4 vs 8 fingers, while keeping your Apple keyboard constant, you might find it useful to see how 4 finger typing feels on TextBlade. The two datapoints reveal a lot about what drives your acclimation rate.
Overall, there is good rationale for adopting 8 finger style, but you could get there in a couple steps if you want to make it easier.
The cold turkey method has its benefits - you can use the new platform as the launchpad to motivate you to advance your technique, but this also removes some bridges to your past experience.
If you crave challenge, you can always throw in Colemak too at the same time, but we wouldn’t recommend piling on more change like that. Practically, it’s easy to get confident quickly with one change at a time.
Thanks for discussing these dimensions, it’s a topic of great interest to many users.