Troy, if a suitable teacher is not available then I think the way to fill that gap is through posting video recordings in #all-about-your-music.
And if you highlight that you really really do want all the constructive feedback that points out shortcomings in posture and technique then there are folk in the Community who are able to provide that feedback.
I emphasised the “really” since here Replies in AVOYP do tend to amplify positives, and not highlight shortcomings as we tend to err on the side of sensitivity, being encouraging and supportive, given the degree of vulnerability present when people getting started post recordings.