Taijiquan, baguazhang and xingyiquan use forms to practice combat movements, build strength and gain agility.
The forms are highly intricate, with many different levels of skill.
Yiquan (mind fist)/dachengquan (the great accomplishment) - an offshoot of xingyiquan - does not use forms.
Instead, it uses static standing qigong postures in lieu of form.
Xingyiquan uses form(s) for power development.Dachengquan uses standing qigong.
See the difference?
What should a tai chi school do?The answer is somewhat self evident, isn't it?
Taijiquan is not dachengquan.
It uses forms, not standing qigong postures.
Read The Tai Chi Classics... There is no mention of standing qigong but a whole lot of information about movement.