I do not think this is correct. Most of the Multitank 6 (25xx tanks) do not have the ridges to hold the sheet films. You may be able to get away with just one film, but not two at the same time.
Jobo is strongly against using print drums (28xx) for sheet film. There are ridges to anchor the films, but the ridges (rails) inhibit the flow of chemicals to remove the antihalation layer during processing.
For 8x10 film, use Expert drum or other devices.