DFC
Your understanding of the effect of grammatical disjunctions differs from mine. Since we are only expressing personal opinions about text that is unclear I'll contact the horses mouth and report back.
On the other point that you're debating with Bose: I don't think anyone is suggesting that Differences training can be done without a practical component, this would be called Familiarisation training. The issue is which of these is required; it appears that the guidance is unclear and that some is not supported by JAR-FCL. As I said above, I'll investigate and report back.
HFD