AFAICT, the newest player software will accept values with or without the 0x prefix. Can someone confirm that this is supposed to be the case?

Yes, it is. The 0x form is preferred though. Having "options" default to hex and all the other numeric fields default to decimal is a bit of a wart IMO but we can't change it now, not with thousands of players full of thousands of files all without the 0x on their options tags.

If jEmplode reads a value without the prefix, it changes it to 0x0. I don't think it should.

Except possibly for 0, I'd recommend that jEmplode writes all values with the 0x prefix.

Peter