@Brandon ***********
yes, i don't consider the AirBNB option being called "for PDF purposes" reassuring just because it's called that. There is no tax ID number and no actual proof of payment, whatever that is. I'll try paying at Booking or Agoda for the whole period with a free cancellation.
Off-topic, on my experience at Penang: I was there on Friday, a bit late, so I couldn't apply anyway. They said there was no multi-entry tourist visa option for me. It was the guy at the gate handing out forms, not exactly the officer, so maybe he wasn't fully aware of my options, though.