The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
Where you feel the strain when sitting cross legged maybe the sartorius area, however, there are a couple layers of muscle there. The satorius is the top layer. It crosses over the psoas and illiacus which are 1 layer deeper.
Have you checked out any psoas episodes and/or daily mIwod?
There are more effective ways to address the deeper layers.