Just as a side note, on the old large 4 cyl road bikes, KZ1000 etc, they used to weld and regrind the cams for performance applications before cores became common place.
Tighe cams in Brisbane will still do this, not sure what they charge for it though. but this would open up a lot more options for the regrind.
On the cam cores - I spoke to a guy at Howards cams a few months ago and he told me a similar story - labour shortage at the foundry who casts their cores so they couldn't keep up with the demand. Having said that they told me 3-4 months wait on my SFT and it was at my door here in Australia 9 weeks later.