I think it's called mortise tang construction when you split the wood in half and have the hidden tang inside a chiseled out pocket. Not sure if it is still called a frame handle, I'm not great on terminology either lol.
Instead of only a piece split in half, one could use a spacer between two scales to hide the tang (similar to three piece laminated saya construction). This would be considered frame construction I think.
Either way, looking forward to seeing the finished knife!