I have a non-standard bathtub drain flange that I'd like to replace (and also clean up the rust) that has a pair of interior nubs. The drain is 1.75 inches in diameter, and the nubs sit about 0.5 inches down from the top of the flange.
I saw two previous questions (one and two) that describe removing a flange with no crossbars/spokes, but can I take advantage of these nubs and use common tools to remove the flange? I'm concerned that the nubs will even disallow the use of an expanding plug.
EDIT: Also, it would be very difficult to remove the drain with channel locks due to how it's seated in the tub.