Paloth, I assure you that I understand what a subpatch is, it's advantages, and it's limitations. As I think I stated, I find it advantageous to have my detail portable between applications.

As for memory limits, it doesn't much matter whether the "things" that are in memory are polygon vertices or patch control points. If memory is an issue, go with a 64bit OS and buy more memory. Also, if you're building complex scenes you usually use a lower polygon surrogate of a character. For a closeup, where you want muscle/tendon detail, you use a higher res mesh. 

Does LW now let you animate displacement maps? If not, there is a need to put the required detail into the geometry.

BTW, was my suggestion regarding your morph problem of any use?