When dviout starts up, dviout determines which font file on the disk should be used for all of the fonts used by the dvi file (reads -TEXPK:, etc.) if font search on demand (-Fod:) is OFF and creates the position mapping between the page and the dvi file.
A larger dvi file will take longer time to display the first page. If the display of the first page is extraordinary slower than page moves or jump, this might be due to too much time for font searching by dviout..
(To validitate the record of the location of fonts) eXit+Save (not Quit) dviout and execute dviout again and choose the last dvi file. Then check the time to display the first page in this way.
Font search will take a long time when // or \ is specified in -TEXPK: invoking kpathsea with -Fkeep: OFF. It is better not to use // nor <<>><<>> for close to the root directory.
By default, all of the Parameters saved in the Registry are loaded at the start-up. By changing the settings in [REGISTRY] property sheet to load only the necessary ones might be good for quick start-up.