Lotus position right knee floating? This isn't a Buddhist question per se, maybe better placed in a yoga or Taoist thread but anywhere here I go:

When I am in the lotus position (classic right leg over left leg as instructed in all Buddhist guides) for the past 10 years, my right knee has always floated a quarter of an inch off the ground, even if I try to adjust my position by sitting offset on my mat.

Anatomically speaking, I don't see how anyone can have both of their knees on the floor..

Although I feel energetically blissful whilst maintaining the posture, the posture feels uneven, imbalances my torso, and I feel uneven pressure on my right thigh and must end my lotus posture in about 10 to 20 minutes due to the pressure on my right thigh...
Sometimes I switch reverse full lotus and that makes me feel more balanced.

Am I doing something wrong or is this something all advanced lotus meditators must deal with?
How can I remedy, deal with, compensate (et cetera) my lotus posture?

Also, this is a separate question but are there any passages in the canon that speak about posture?

Any suggestions in any realm, physical, environmental, or even mental are welcome.
The position is something that your should choose to help in meditation, i.e., being able to be in the position for a long time without issue. Dwelling too much on what is the right posture is leaving the main task at hand and concentrating on auxiliary tasks. The danger in this is that this can lead to trying rights or ritual like practices which has been case in some schools of Buddhism and in India.

Also any your posture can be taken into practice of the 4 frames of mindfulness. The posture it self (sense through the outline of sensations) and the pain that results from being in it for a long time.