I have a question pertaining to DCC. I know it's almost always a good idea not to request DCC but wouldn't be more advantageous to request it in some instances in which there's a high probability that you might request a full refund?

For instance, let's say you make a hotel reservation and you're charged a deposit of AUD500. You're charged the equivalent amount in USD or around USD362. However, your travel plans change and you cancel the reservation later on. The hotel then refund the same amount of AUD500 that they charged you but by then the AUD has lost some of its value in relation to the USD so the refund ends up being around USD357 after currency exchange. The foreign transaction fee refunded is also less because of the lesser refund.

On a side note, if the AUD would have appreciated in relation to the USD, would I have received a slightly larger refund? I've never received a refund larger than the original purchase amount.

Wouldn't be better in these instances to request DCC from the hotel (assuming they allow it) so that the amount charged and refunded in USD doesn't fluctuate as per forex rates?
And if they did, would they initially charge and refund you the exactly same equivalent amount in USD or would they convert each of them depending on the current exchange rate?