A page file on a RAM FS drive is not supported, and it is not something we expect to support. RAM File System is a file system driver that loads well after the point where Windows sets up the paging file. By the time the volume exists, the memory manager has already decided what it has to work with.
It is worth adding that it would not help even if it worked. A page file exists so Windows can move data out of RAM when RAM runs short. If the page file itself lives in RAM, every megabyte it holds is a megabyte the system can no longer use - you would be spending memory to relieve memory pressure, and ending up with less than you started with. The memory manager would also have to page through a driver that itself needs memory to do its work, which is the kind of loop that ends in a stall rather than a speed-up.
Our advice is to leave the page file where Windows puts it, on an SSD, and use RAM File System for the things that genuinely benefit: temporary files, build output, caches and scratch space for large files. Those get read and written constantly and do not need to survive a restart, which is exactly where the speed shows.