I’m torn on this question for several reasons. First how thick a 1/4 full bury prusik is. That’s a big prusik and you would need to bury approximately 13” in each direction for it to be the correct holding strength. So your prusik would also be very long.
Secondly all guides to friction hitches suggest a reduction in size to 60-80% of the lead rope (a Blake’s hitch and a couple other single leg hitches are exceptions and can be used on the same size line). However since amsteel bites down so ridiculously well, I would love to see it drop tested to see how well it holds at that 100% sizing. Whatever you do make sure you have a large well tied stopper knot on your main bridge line, just in case and if it does slip, replace it immediately because amsteel has a low melting point compared to other ropes.