Installing Extensions using GUI versus Composer

In our setup of Opigno 2 we found it was much better (and way more time intensive from the outset, but less so in the big picture) to install all of our extensions with Composer via commandline instead of the GUI, because Composer keeps track of all dependencies and automagically keeps everything copasetic. Does the same hold true in Opigno 3? Does the extension section function the same as it did in 2? Or could we possible ditch the labor-intensive Composer for installing extensions?