I spoke with DD's speech/feeding therapist last night. Turns out that the high chair we have at home is causing a lot of the feeding issues we have with DD.
It turns out that if DD is in a position that doesn't activate her trunk muscles, she uses her TONGUE(!) to balance herself. Which hinders feeding because you can't eat with your tongue out.
Her recommendation is the Stokke Tripp Trapp. It's expensive, but it will carry her through adulthood as an actual chair. The therapist also wants us to get DD a more medically study stroller, but luckily the PT and OT disagree. Especially since we're working so hard on getting DD to walk.
Seriously, this is so beyond frustration just across the board. And expensive. Early Intervention might be able to help, or the therapist might be able to write a letter to insurance to get the high chair covered as a medical/therapy necessity. Regardless, it's a PITA. And just one more thing on the heaping plate-o-crap.