Sure you could, Scott, but is it really worth your time (grinding the edges away from each t-nut) to do it?
I've found that even with the screws on the outside edge, the protection and stability afforded is good. Another thought about your notch idea is that it would put the screws close to the drill hole.. making for a weaker foundation for both screws and t-nuts..
To the OP: I use exclusively the legged t-nuts for the last 35 or so years.. with no issues. I have used the screw-in attachment method described by John successfully as well.. but have found a better method is that being as most t-nuts are near openings.. a pair of vise grips or a small bar or C clamp does a great job at swaging in t-nuts. Just use a small piece of bar stock on the opposite side of the wood from the t-nut.. especially with the vise grips. A bit slower than pounding in.. but more effective..
Last, I have used the epoxy/glue/silicone rubber method for attaching/ permanentizing t-nuts.. and I have found the screw method, or securing a block of ply above the t-nut with 2 - 4 screws straddling the t-nut to be far faster.. with better hold results..
Regards,