The Dora is only marginally slower in roll than the Anton according to Wright-Patterson postwar evaluations. Brown's Dora is actually a D-12 by the way, nobody knew it existed at the time so he wrote it up as a D9, they didn't find out until it was transported to the US, it's the one that in their smithsonian I think it is. It's a hand finished, specially prepared service evaluation D-12, a very finely made aircraft in limited series. It does not in any way reflect normal Dora performance in any regimé, Wright-Patterson tested captured service examples and found build quality so shocking they had to rebuild them before they were declared airworthy. Then they were surprised that something so rough could match a Mustang, but it felt like it was falling apart while doing it.
The reputation of the Anton's snap roll isn't actually from a roll. It's a controlled stall, and only the Anton can do it because the radial, the wings and the stub fuselage make it slightly unstable in banks and level turns, actually makes it very spritely all round for any rolling kind of flicking manoeuvre. Would love to see one matched up with a 1944 Zeke 52/62 on water-injection or a Ki-84. They're stable but highly manoeuvrable, the Anton is unstable so extremely agile.
Doras are a little more stable because the torque tanslates along the monocoqué via a rather long block, not all on the crank with no real engine block at all. Still got more of it to lose but. Wright-Patterson found the Dora superior (to the Anton) in all respects. The Antons they tested were an A-8 and an F-8 by memory, but the F-8 already had the fine tooth comb from the Army back in 45 so got written up in all their training manuals on German wartime technology.