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No, it didn't change anything - but your suggestion made me compare all the boot config lines. Yes, when disabling DMA, I was able to run 3rd "mode" as well - still: the graphics remained as ugly, as in 4th one.
What a pity, that it's so cumbersome. IMHO it has been released to early (at least as "regular" release, with no "beta" neither "pre"), without being well-tested.