I would avoid the drilling also, just ramp down with a through air blast if you have it available.
There is one possible benefit of having a couple of holes.
Since they are through, there is a better chance of chip removal when the pocket gets deep.
IOW if you cannot blow them out, they might just fall through.
But then again, 225IPM for only 1.5" length doesn't give the chips too much of a head start....