I haven’t tried it, so I know absolutely nothing about it. Now that you know what my opinion is worth… I say you’d likely be fine if you do it within reason. The fact that there is so little pick exposed with your grip should mitigate any problems with increased flex or breakage. Mine (the bluegrass model) have five columns of holes. I would try punching two holes in the same spacing with columns 2 and 4. If that wasn’t enough, try adding one more in line with the middle column (I drew a pretty picture below). To my eye, it looks like there would still be enough meat around it to prevent breakage.
Edit: image removed because it didn’t format right… darn html
Geek alert! The holes measure out to 0.117". I would guess that is probably metric. If you have index bits, a #32 will get you closer than my eye can tell (0.115"). If not, a 1/8" bit is close enough for government work.
If you want, I have a couple 1.2 Wegens I don’t use. I’d be glad to experiment on them and test it for strength. Just let me know.
Again, drill at your own risk. I love posting about something of which I know nothing. It’s easy for me to say your pick won’t break