I took the time to actually measure the tool rest dimensions. The tool rest on my G0766 actually sits below the center line [measured with spur center in spindle, from the point to the top edge of the toolrest] in an amount of 5/16" below the center line.
This is not too bad.............consider this.......as your rest gets nicks and dings in it, the recommendation is to take a file and smooth those out, which will of course take off a little metal.......in time that will add up.
If you feel like yours is too high, then take a measurement like I mentioned above and then post what your results are...........measure carefully, so we can get an accurate spec.....we can compare notes, and also if you feel like yours is just a bit too high, then you have the option of filing down the top of the rest a bit as well.
Aftermarket rests with no stop machined in the post, will not matter as long as the post is long enough. I took the time to take a 1" silver and deming twist bit in the drill press and put some oil to aid the cut.......the hole in my banjo is now 1" and slick and smooth.........if you decide this is what you want to do with your unit, then just be careful doing this and clamp that banjo down securely. I had to put mine on a block of wood to allow it to sit flush because of the clamp bolt underneath.