That is true about being hosed until you make it fit.
The rest is academic.

Either way, make it fit by what ever means you have to,
Get Cai to the races and to be able to practice on the race bike, and the rest will pretty much take care of it's self.

For the record,
I have only cut 2 head tubes (other than just a VERY minor facing here and there for assembly that would normally entail just taking powder coat or peoples paint off where they didn't mask it)

1 was for a guy who dropped a brand new frame on a concrete curb and left a 1/16" mark in the upper face, and the one on my bike as described a page or 2 back where I made more clearance to fit the desired equipment being big tires on an old school bike.
The first was easy, just reface it and he was happy. 1/16" is not much to worry about and it came out perfect.
The second was mine and the bike is still ridable and in my garage today.
No adverse effects were noticed. I still use this bike quite a bit for urban assault rides and at the local BMX track to play on the jumps and pump sections.
Yes, it did make it more slack, only a little, but more slack none the less, lower crown got moved up,
and I think from there, we've beet this thing to death.