I wondered if it's a practice run for the US, although it's possible the process for "managing dispute evidence submissions" is more involved in the EU. They seem to do next to nothing in the US — just forward the docs you upload to the customer bank, I assume.

I agree with 2 — this would be really bad if a business were targeted with chargebacks. There would need to be some defensive mechanism that kicks in and retroactively refunds all these fees in such cases.

I also wonder if this is just a way to pump up their margins in advance of an IPO.