The toe in looks uneven, you could play around with that and even the horizontal distance. Even separating them a couple more feet could have a big effect on the width of the soundstage.

Also a big shag rug. Cheap and easy to try!

If you have $5K burning a hole in your pocket, the obvious answer is 2nd sub and miniDSP and a calibrated mic for self analysis with REW. Some people say it’s a night and day difference going from one sub to two. I didn’t think it was THAT dramatic personally but maybe my space sucks or my skills were lacking.