Do you think this would make a difference?

Air flow during a PCP's shot cycle is largely turbulent, not laminar. When the valve is knocked open, air flows around the poppet into the valve throat, turns and goes up through the exhaust, through the transfer port and barrel port, and turns again to meet the pellet. It's a pretty chaotic "journey" lasting a few milliseconds. Rounding edges and trying to guide an imagined column of air helps a little but it's pretty mundane compared to, say, just opening the passages up. Of course if the passages are already opened up as much as the parts will allow, rounding things off is the last little thing that can be tweaked. Given the small effort usually required, I'm an advocate of doing it.

Another thing that can be said about the bolt probe being drilled too deep is that it represents an unnecessary volume that must be pressurized during the shot cycle. Frankly all the volume between the valve seat and the back of the pellet is wasted volume that would not exist in an ideal world. Minimizing it will have a positive effect on efficiency / shot count but it would have to be really deep for you to see a meaningful improvement by filling it.

interesting stuff!

I think Chrony and accuracy will be the best judge! keep us posted!

if that is the only TP you will/might have more FPS, if there is another one you probably will need to enlarge that too so they match