Yeah I tried to find the rates that Swish charges to businesses but didn't find them (although didn't look to thoroughly either). But can it really be even below the 0,2% of cap for debit cards?
Swish is 1 to 2 SEK (2 being the list price that can be negotiated) per transaction. Then swish has a daily cap of payments you as user can do of 150k SEK (system limit, not a soft cap that the user can remove).
That is an extremely low limit for any noteworthy business, equating to $500k USD a month total. Most small grocers here in Seattle do more than that in credit/debit monthly.
The Swish limit is for outbound payments, not total transactions.
So a grocer that accepts Swish payments will in no way be hindered by this limit, unless they for some ungodly reason are also swishing money back to customers.
The rates for Danish MobilePay were easy to find [1], and are flat, under 30-75 ears [2] depending on volume. I'd guess that's around 0.5-1%, but I don't have much idea.