The 's pilot texture files for many of the older AH2 aircraft are included in their list of files that can be submitted by a skinner. The new P-38 skins may still have these old P-38 shape pilot files listed on the submissions site but this is just an oversight by HT, they are obsolete for the new P-38 shape.
The new P-38s use HTC's animated pilot which they developed to work with VR systems. There are a few other aircraft using these including the Lancaster but it seems there is only 3D model and texture for the VR pilot and that is the desert RAF one made for the Hurricane IID. However even if HTC added this VR pilot's texture files to the ones that can be submitted with a P-38 skin it wouldn't really help. The VR pilot would still have the 3D model of an RAF desert uniform with short sleeves and shorts and there is no way it could be made to look like a USAAF or any other sort of uniform. Really it needs HTC to create new VR pilot 3D models and textures for each air force, which is a fair bit of work.
BTW I didn't skin that Japanese pilot.