I think it will be a moot point, as Qantas will cover anyway.
I was caught in Melbourne, on a day trip - no luggage at all, for a Wedding (whcih was Saturday morning, so no problems getting there). This was actually a quick trip from Sydney, where we were visiting, and then returning.
I knew that the Amex Plat Charge insurance would cover accommodation and food and beverage due to delay (or cancellation / denied boarding), so safe in this knowledge, booked hotel ASAP before everything disappeared (only Derby day in Melbourne, and the morning flight down was full of obvious racegoers, and one Tony Abbott as well).
I didn't have the PDS with me (not for a day trip), and had no luck finding the website link using the iPhone (only found broken links - should have browsed the AFF threads which have the link). Eventually (after no luck with the insurance number - they can only do claims, and don't have copies of the PDS

), got the concierge to email the correct link.
This confirmed what I suspected - emergency clothes (we only had what we we wore to the wedding, so not suitable for walking around on a long delay), would only be covered by "delayed baggage". I am not sure that arguing the baggage was delayed in Sydney (we were mid way through a multi-city booking, heading back to Sydney) would really work, as it was never checked to come with us to Melbourne anyway.
Having seen the initial Qantas offer, the plan was to get them to cover under "incidentals" anything we had to buy, and then use the Amex for food and beverage (hotel was going to be inside the QF limit), if Qantas wouldn't cover.
Have claimed everything via Qantas (actually hit twice, as was supposed to return to BNE on 30/10, separate PNR to the 29/10 MEL-SYD), and expect them to cover it all.
So, despite being happy with the Amex Plat Charge included insurance, I have stumbled into a gap in the cover, albeit, not one that I am particularly concerned about, but it just goes to show that you really need to know the details of the insurance coverage.