Articles like this always paint a rosy picture of the 3270 but consider the limitations. Async style updates as commonly found on a VT designed program were tricky.
Now admittedly my own experience with the 3270 was through about three layers of obtuse IBM operating systems. Perhaps if I sat down with a 3270 and a bare OS I would consider them differently, but I always found them terribly limiting compared to a VT. More efficient sure, but much harder/impossible to do cool stuff on.
source: I was a night shift tape monkey for a IBM place for a few years. A fair amount of down time, access to a full set of manuals and an understanding boss meant I was doing more hacking on production mainframes than I probably should have been.
I'll give you props for studying the systems manuals and not the handmade Adventure maps drawn on green-bar paper and hidden behind the back of the last 3270 at the far end of the row of tape request consoles.
I was on the DEC side with an amber VT220 and always thought it was cool that the 3270 could scream "mount me now dammit!" in flashing red block letters while the operators weren't sure if they should drop the keys or pick up the lantern.
They optimized for different things. The instant responsiveness of the 3270 vs. the VT at Xbps for local editing was nice. You could do async updates and even async input (via polling) as well though there was this annoying thing where the input could clash with the output and you'd get this weird icon that you had to clear (my brain is iffy on the details) e.g. when you hit a PF key while the display is updating. I think there was some workaround. I wrote some games that ran on the 3279 in an async mode (using some utilities a friend of mine built for that).
What sort of data were you work with back then? Bank stuff?
It was a mid sized mail order company, they had invested early with computers, and not changed much since. It was a very strange mix of odd old computer systems. An IBM mainframe batch processing backend with sco unix on the front end using pick databases as a sort of vertically integrated database and terminal ui.
When hired I had just missed the retirement of some sort of lockheed minicomputer they had used in the call center, which I would have loved to see. It was a very odd environment.