Can I coat it in poly over the TO after buffing it smooth with the steel wool? At least then I could do a regular wet sand and buff.
Keep adding thin coats and it will level and be beautiful. Each layer refracts the light a little differently and the more there are, the more pop and shimmer you get. A thick clear coat won't show the grain as well.
Think of a bar top with the poured acrylic over stuff like pictures and labels or the menu. That is the extreme, but if there were multiple layers, the light would polarize in some places and make the menu hard to read. It might look really trippy and wavy, like distorted glass. Which, on wood, is a good thing. It carries light into the grain pattern and bounces it around, sort of like inside a faceted diamond.
Many properly applied thin layers will always treat the light better than a single thick layer. That's why beautifully hand-rubbed fine furniture is expensive and takes a long time to build. It's not construction, its preparation and finishing that takes so long.
The opposite is a factory production guitar painted in the newer polys. One thick coat, UV light cured and crystal clear in 15 minutes. It's like looking through glass. The light goes straight in and bounces straight back out. Does nothing to make the figure in the wood pop. If that's the look you want, I'd use a 2 part automotive urethane.
This is all dependent on your prep before any finish was applied. If it has high spots, low spots or any other spots that need to be wet sanded out, it probably wasn't ready to finish. It must be in final form, before anything is applied. Wet sanding is a very quick task if the prep work was done completely. It should be nothing more than leveling any orange peel. Not leveling the wavy surface of the guitar. Only exceptions being trash or bugs that fall in the wet paint.
Just my way of thinking. It's still your project and your choice.
The finish will never fix a problem, it will only change the color and make it more obvious to the trained eye. Isn't that really the guy we all want to admire our work?