How do we know that regulators won't like being mocked by Apple's lawyers? I can't think of many reasons why anyone would like that other than bribery to smooth things over.
Apple's entire plan is a farce that further illuminates the deathgrip they have on the entire platform. Preferential treatment of their own app store, requiring Apple's approval (notarization) of any app, regardless of distribution channel, their ability to revoke any developer's ability to publish app, regardless of distribution channel, etc.
I'm not a lawyer so I'm not going to try to interpret dense legal text. We know what the spirit of the law is and I'm operating under the assumption that (1) EU regulators intended to effect real change, otherwise this discussion (and the regulation itself) is entirely pointless. (2) It's obvious that Apple's proposal makes no difference to the status quo, it just highlights the extent of their anti-competitive position.
Therefore it's reasonable to assume that the regulators will not be happy with the proposal unless (1) is false.
If you read the website about the DMA they are talking about business independence, user control, transparency, access and interoperability. There is no mention of fees - so a reasonable fee doesn’t look like it would cause issues.
