I think the reason for such large holes in 65-note music was to match
the size of the bleeds in the valves.

I say this because there was a time when Ed Freyer was making recuts
for coin pianos, and while the hole spacing was correct for 6-to-the
inch, the perforation size was much narrower than the original rolls.
(I was told this perforator was also used to make Link rolls and that
was why the punch size had been altered.)

A lot of coin piano owners had trouble playing these rolls because
their instruments perhaps were not in great condition at the time.
Some folk actually reduced the bleed size so they could play rolls
from Ed.

Regardless of the length of the perforation, if you are not uncovering
the maximum or nearly maximum opening in the tracker bar, you can not
get a strong signal to the pouch to give snappy and positive operation.
Reducing the signal to the pouch with a narrow perforation, and then
overcoming this weak signal with the standard size large bleed, will
give you a very poor playing result.

As I said, this was on instruments that were not in excellent condition.
If your piano was properly rebuilt and tight, the Ed Freyer rolls could
be played well.

This is what I recall from those earlier days.

Best,
Ken Vinen, Stratford, Ontario, Canada