Your diplomatic approach and tone is extremely commendable. As is your openness to see both sides. This is definitely a make or break point; you’re right about that!
It also comes down to what the consumer will use it for. If it’s for a gaming device that just happens to use a keyboard, and is held in a “handheld” fashion, the mini keyboard would certainly be my cup of tea. For development, I would use a wireless BT keyboard and mouse, and only really use the built in ones while commuting etc.
From experience, using a mini keyboard on my old Cassiopeia was useable on a desk (propped up - I’ll talk about that in a moment) balanced on the palm, with another one typing; single handed, or typing with thumbs, handheld.
However! One handed typing would probability better with Dvorak; and hopefully the key caps can be reconfigured. If not, the option go buy it configured with different caps could be an option.
Desk use would probably need to be propped up on a slight angle. My Cassiopeia had a kick stand, but I don’t see one on the devterm at this stage. A base with a prop up portion shouldn’t be too hard to make. Perhaps even a hard shell case that can act as a stand could be made.
Personally, I am for the mini keyboard vs the mx keyboard. My biggest fear with the latter is portability, weight, and sustainability. As mentioned above, the keys would stick up, making it take up far more space, and if it is to be something portable to put in a bag, more prone to debris falling in. The current membrane would still receive the debris, but would keep if contained.
Of course a second point to take in is cost. It’s not a cheap device and adding a mechanical keyboard on top of this would make it outside the price range of most people. Definitely as an upgrade later on, but not as the default stocked configuration.