I think the most obvious is loss of workspace.
Second is overall stickout of the actual cutting surface screams chatter with a fly cutter.
To me a mt socket doesn’t seem right for side loads. Drill op’s would be fine maybe a boring head using minimal doc.
My thought would be the mt socket gets deformed when you snug the endmill holder setscrew. Causing the mt socket to not hold properly. Idk. I only use mt shanks for my lathe.
Why not replace the shanks on your boring heads to a straight shank?
Second is overall stickout of the actual cutting surface screams chatter with a fly cutter.
To me a mt socket doesn’t seem right for side loads. Drill op’s would be fine maybe a boring head using minimal doc.
My thought would be the mt socket gets deformed when you snug the endmill holder setscrew. Causing the mt socket to not hold properly. Idk. I only use mt shanks for my lathe.
Why not replace the shanks on your boring heads to a straight shank?