I've done plenty of "his and hers" master baths where "his" was only a 24" or 30" single vanity while "hers" was 48" or more. But, the room design didn't depend on symmetry, just the overall visual balance that involved the other elements visually taking up some of the space. When confronted by one of those uber symmetrical spaces where equal sized vanities flank a tub with a window behind and it's all viewed as a whole from the door, you're going to have a much tougher time making that look good without sticking with symmetrical choices. Post your diagram of your space for some more informed choices to be suggested.

problem solved ! A friend dropped in who had the same problem in the past. We picked up a couple of 3 inch abs 45 degree elbows and a 90, along with a new coupling. We attached one 45 directly to the coupling and the second 45 directly to the first, creating a 90 with a "gentler curve", which reportedly prevents clogging, We hen attached the 90 at right angles to the two 45's to accept the toilet flange. The result placed the center of the flange 12.5 inches from the wall ( acceptable ) and only 2 inches to the right of the old midline, thus not crowding the vanity on that side. Excellent,!! How come I hadn't thought of that ?

Aiden - thanks for your response. I will have to remove a lot of the drain line to be able to do it properly, but it WILL be done right. Fortunately this section of plumbing is isolated from our primary bathroom, so I can take my time. And I'll be taking out some of the hodgepodged "fixes" they did before, so maybe this is a blessing in disguise. The guy is a licensed general contractor but he usually subs out his plumbing work. Wonder why! He didn't on our job because it was supposed to be so minor. Unfortunately he's already been paid, two years ago. I'm doing the rest of the reno myself. I've had 2 babies in the intervening years so it's been slow going, made slower by the fact that I keep having to re-do stuff that they did wrong.

I thought the actual vent would be stacked above the main vertical drain, which runs down to the basement toilet location (i.e. down the west wall). Also, this is only a 1" diameter hole. I'm still puzzled. Ted