This is just an observation, but sometimes when I’m using other keyboards (factory keyboard or Gkeyboards), when I’m filling email field in a form, the keyboard would automatically change to a different layer that had “@” sign on it. Or, typing in URL bar would bring the layer with “.com” or “www.” keys on the keyboard. Or, typing in a numeric field that only allows numeric input, it would bring up the keypad layer.
I think, but I’m not sure, I already see this happen with keyman keyboards for “numeric” layer to be brought up automatically in some forms, but since most of the “numeric” layers are basically numbers + symbols, it feels different from “keypad”, so if this is true, then I can experiment probably with an “email” layer, or “numeric” layer that looks like a keypad
(minus the autocomplete suggestions)