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

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.

Thanks for the advice. I'll call Wendel. We probably have a great deal in common in terms of quality fundamentals as I have been in the quality/technical field for 25 years.

I'll keep you posted....

I do not understand your problem. When I sit in my seat my ears are between 4' & 5' from the floor. The sweet spot is never at floor level because the speaker drivers are not horizontal along to the floor but vertical from floor to ceiling except center speakers for HT.

When I'm sitting in my listening chair my ears are 3.6 feet from the floor. In my case the music is much more dynamic and engaging at 5 feet plus.
By manipulating the speaker placement in my room, I was able to lower the sweet spot somewhat. It's much better now thanks to feedback I received from this thread.

Is your head above the chairs back, also do you use a chair or couch? If you sit forward does the sound also get better? Where is the sound stage, high on the wall or at head level and lower?