Room Treatments for Maggies

I own Magnepan 3.6s
I have them at the 1/7 distance of full room depth. This is to avoid other even fractions of the distance. This is actual 42" out from wall behind speakers (for my room size) with the tweeter at the 42" (as the speaker is toed in) with the tweeter on the 'inside' rather than the outside of the speaker pair.
IMO 1/3 is impossible in the average room, so try 1/5 or 1/7... actually calculate the distances. 1/3 is only reasonable if the speakers are on the short dimension wall.
I use tall bookshelves on the rear sides, (right up to corner) then the back corners happen to already be heavy draw drapes, opened. Middle back is a very large window, just have stuff on sill, plants etc.
The speakers are toed in about 30 degrees. And are rather close to side walls, about 18" from side wall to outer edge of speaker.
Very similar to the picture of the recent audio show, in which a room the maggies are near the side walls. mine very similar position.
I sit out into the room so i am about 10 to 12 ft from speaker plane. With room to walk behind the listening chair.
Feet: if the feet are on hard ground, the speaker will be brighter. If the feet are in soft carpet, the speaker will sound more mellow. You can stick thin bits of thick nails etc at ends of speaker feet if sof carpet and the speakers will be brighter, and bass firmer, but it is a big change in sound for such a small addition.
tried just pins under the bass side, and not the tweeter side, and finally went back to nothing extra under the feet ends. (mine are on soft carpeting)

I would try to stick something under the end of the legs to squeeze them up a bit. I used some pins for shelving, one under each end of the legs (total eight pins) You could use some thick 3/16 diameter nails, stick the heads out each side near ends of legs (16 nails would do it).
They really stiffen the speaker. If you rock the speaker now, it will sway XX amount. If you stick the nails or pins under the ends, and then try to sway it, it sways way less! and tighter. And the sound is tighter, and brighter too.
If that helps but is not enough, then try the solid something under the legs.
I would try something like a large patio stone if you want to place a solid hard object under the speakers. 2 foot diameter round cement ones are about 75 pound each, or a 24" or so square ones. You could paint them flat black (if concrete, they will take a ton of paint! to cover them. I know)
I used to use round concrete slabs under my previous speakers, Infinity RSIIa.
I put the slabs on tip toes, and the speakers on the slabs, to cut the bass going into the floor (apt dweller)
Using a solid base, not a thin metal one would be better.

IMO typical room treatments will make your place look wierd. You better already BE married, cuz few and far between will be the women who will dig the look you will have going with standard room treatments. Use the normal stuff people own, instead of outer space trinkets.
Just sayin'.

"Perfect stereo sound.... or a normal life.
Your pick.

No. The speakers OK, room treatments my be the straw too far.
Treatments are TEN TIMES uglier than the magnepan speakers.
So .....
One of your wifes friends might ask what are those? (magnepan ) and the answer would be reasonable/slightly annoyed.
Room treatments, The answer would be a string of obscene comments...