BA's second response reiterated their £500 limit for two nights of hotel, but said they would also reimburse our taxi and meal expenses. They appear to have left off one meal expense that was on the hotel bill. I'm not sure if that was deliberate or inadvertent. I'll send another response pointing out the discrepancy. I had also submitted $24 in roaming cell phone charges. There was no mention of those in BA's response.

Perhaps it's BA's strategy to shortchange the reimbursements each time, hoping the difference becomes small enough that the customer stops pushing back.