New visitor here on the forum.
I know there is a folder where manually created presets are located, which is in C:\Users\Name\Documents, but only OFX presets are saved there, such as plugins from Sapphire, Boris Continuum, Vitascene, among others. In the case of DirectX presets, such as native Vegas effects and transitions, Pixelan plugins, and older versions of NewBlueFX, I can't find a way to locate them, and I need to make a backup, since I lost my own presets that I made years ago, and it's tedious to recreate them from scratch.
Here are some screenshots of ones I made recently (they are not OFX):
https://postimg.cc/rzd6DzD0
https://postimg.cc/dDZXqXfm
https://postimg.cc/5jz7czHw