well most phones do try to lock their nvram, htc is notoriously good at it tho, not as good as motorola, but still pretty good. im sure theres a way to do it, there technically has to be a way, but it would be unbelievably difficult, samsung however used a standard rfs file system on the nv block, so once someone was able to figure out which one was the nv block all you had to do is copy it to a pc and open it with magiciso like an archive
as far as needing cdma ws though that is correct, unless you want to use qxdm and qpst, but editing the nv is so much easier with cdma ws, i even made a program that pulls the correct file, you then unpack the right nv items, and it can translate them to the correct format to upload directly into the new phone. qxdm requires manually editing one hex digit at a time... ive done it, rather painful process, writing the script to convert from binary to a properly formatted text file probably took less time lol