Yes, it wets out the grain well, possibly not quite as well as epoxy, but then they are both sanded off back to the wood.
I have offered wondered about just levelling with finish alone, but didn't know how many more coats I would need. That is great info.
When And if I do pore fill with this polyurethane I will certainly post the process and results.
The company that sells it is a one man operation, and all his products are bio safe.
Www.skinboats.org. While his business is a skin on frame Boat building school and store catering to the skin Boat community, I think this might work for guitar finishing. I certainly wouldn't use it for a final finish, as it is thick and would kill the sound, but pore filling, maybe!