Thanks for mentioning my "VDC FLI". As mentioned on CSDB in the production notes, this mode originated in the "Risen from Oblivion"-demo. With a lower vertical resolution or better timing it should be possible to do exactly 60 or 50 Hz in that mode, but calculating this with the necessary register-switch is a challenge on its own.
Too bad the REU can't access the VDC-registers and DMA only works in 1 Mhz-mode as mentioned in the REU-manual. Emulators are still catching up regarding VDC . Z64K should be the best one in that regard as you probably know.
I know the 128-version of "Attack of the PETSCII-robots" uses MMU zero-page relocation as well. And then there is the "Andropolis"-demo "Doomstage"-demo part that uses 2 Mhz as well as MMU-zero-page-relocation for speed-up.
Will have to take a much closer look at this game :-) Thanks for keeping C128 alive.