Well, as usual the answer is “yes and no”. The official description is very clear on how Just Type works. Indeed, one can still use the gate inputs to trigger sounds (independently from the note values Teletype is assigning, in case that’s important—it would take some thought or typing to have the gates advance the sequence), and if you’re careful with your scripting you can even determine which inputs will correspond to which notes.
As mentioned in the link, in synthesis mode you get some control over the built-in envelope shaping, but it won’t really follow an external envelope generator. You could always run each output you’ll be using through its own VCA, but given my vague understanding of your setup that seems out of the question.
