I'll keep this brief because I'm sure everyone is sick of hearing about flanges.

It appeared that Jake had finally found a floor flange that would allow an EMT compression connector to be fully threaded into it. WOOHOO! I ordered a bunch of those "AM 1949" flanges from Amazon as well as from another seller. Of the 8 flanges I received, only one allowed a compression connector to be threaded in more than a turn or less 😞

Not to be deterred, I was determined to make the connector/flange marriage work.

My solution: I ordered just about the least expensive 3/4" NPT tap Amazon had to offer. I clamped the tap TIGHTLY in a vise. Next, I screwed the flange to a long scrap of 3/4" plywood. Finally, and with some amount of effort, screwed the plywood-mounted flange onto the tap. The photos tell the story better than words.

Bottom line: Following the forceful application of the tap, the compression connectors were at last able to thread fully into the flanges. I now have a lifetime supply of compression connector equipped floor flanges. Don't ask me what I'm going to do with them.