I found the sweet spot but it's 5ft off the floor

More setup info would be nice.....I too have 1.6s, and think as shipped they are a little beamy.
My first reaction would be to flip 'em around and listen to the OTHER side of the speaker...the side that you can't see the mylar from. That's right, put the connector/fuse side FACING the listener. At the same time, experiment with tweeter in/out. Make sure you have enough room in back of the speaker, too. Most like at least 5 feet for rear wave time reasons.
Also, are your panels straight up or 'tilted' with the spacers? Try 'em straight up, if tilted. Lay the panel face down, flat on a large table to do so. That'll take the stress of the stand screws.

When you get them exactly where you like them, get out the long tape measure. Measure from the side stiles to the wall. Measure inside between 'em. Measure side clearence to the walls. Write it all down.

Rac,
Maggies are shipped with tilting spacers. IF the speakers in question have the little nylong spacers installed on the bottom screws of the stands, that tips 'em back. Some owners like them tipped back, others like myself, go with straight up/dn.

In general, I've never heard of tilting them forward. You will start getting floor reflection problems, which depending on ceiling height and IF they are indeed tilted back, may actually be the issue.....ceiling bounce.

Have you tried a L/R swap or tweeters in/out or ANY modified setup.
Some of the folks over at Audio Asylum / planar division may be able to help.

A few over there put the speakers EDGE ON to the listener, sitting in the side null point and relying on reflected sound. The claims are pretty ambitious.

How much toe are you using right now? Are the speakers IN PHASE? Please check 2x! Swap one +- to be sure. Are BOTH fuses OK? Pull 'em and check with a meter. 4A fuses sometimes pop and still look OK.

Since I'm not there, unless you are local, in which case a housecall will cost a beer, you're going to have to mess with it until you get it. At some point, IGNORE THE DIRECTIONS and just try anything. At some point, it'll click.

BTW, 11x14 is an awful small space for Maggies. This may be the 'root' cause of your issue.

Switch,
good, your doing the right stuff with setup.
Toe? IF both edges of the speaker are the same distance to the front wall, ZERO toe. This is almost always a bad idea. Toe IN is generally the way panels are arranged. Toe in will be when the line straight from each speaker crosses in front or in back of you. This will adjust image width and can sometimes result in a hole in the middle. Toe 'in' results in the outer edges of the speaker being further from the wall than the inside edge.
Some even recommend placing the speaker EDGE ON to the listener. This is another set of experiments.

Again, you have a smallish room. I have used Maggies in such a small room many years ago and basically listened near field, making my panels into a huge set of headphones.

You are past my direct knowledge.
HOWEVER, I'd recommend posting at Audio Asylum....in the Planar section.
Post a picture, too.

Magnepan is frequently knocked for quality issues. Given the bang/buck ratio, people tend to put up with it. I woudn't, and if I had the chance to speak with Wendel, quality would be my #1 concern. I've had extensive quality training and bring some real experience to the table. I'd work for a couple months for a pair of 20.1s, and help with all quality issues.

Magnepan, I'm told, changed glues sometime back. They formerly used 3M77 and an overcoat. The DIY crowd likes Gorilla Glue!

Post back with results of your querry to Magnepan. You can call 'em, too, and ask to speak with Wendel. He's a great guy to deal with and the 'go to' man.