Cool idea! I'll try my hand at it. I'm mixing a few of the 190 fisheye Originals and the 200 fisheye Originals though. Let me know if you prefer just one or the other.
45 degree Reclined Seated POV works best for cowgirl IMO.
If the recline is too steep, then the FOV shrinks too much.
If the recline is too shallow, then it's almost like laying down POV but not as good.
Both the recent Kenna/Skye and the ACC/Bella were good examples of 45~ degrees:
45 degree recline also wells really well for teases and body licking, because we see more than just the top of their heads, and we can actually see their faces looking upwards:
Close-Up Missionary, well Nash is the master of that. There were some points in time (a year ago), where the position was too close, or too above, but those have been worked out and things have become super consistent nowadays.
Good example (Kenna/Skye):
Not As Good (too close and too above, Kenzie/Tru):
Laying down Cowgirl. I'm going to deviate a bit away from Master Nash, and say I actually really like VRFanservice's laying down angle in this scene. This may not be the best screenshot of this, but there is a lot of headroom in this shot, and there were moments in this scene where the performers could lean all the way forward and do "hoverface" cowgirl, which is when their faces are leaning super close, and hovering above the viewer's face. I think in order to achieve this, the camera needs to be very low and angled slightly upwards. The male nipples/torso still need to be in view of course, but the key is to have that ample headroom for ultra close lean-ins.
That's all I got for now =) Must get back to work!