maybe i dont understand well your question relative to the ARG scrolling container:
-the container scrollbars (V and H) are very fast manually.
-it can be coded programmatly externally to scroll some distance in pixels for ex .

*add this procedure to the main prg
*can here with upArrow and DownArrow make the container scrolls automatically with a wanted value to set.
*add

keypreview=.t. &&to definition form class at top code

PROCEDURE KEYPRESS
LPARAMETERS nKeyCode, nShiftAltCtrl
local m.n
m.n=300  &&to set here the wanted value
if nkeycode=5  &&up arrow
For i=1 To m.n
thisform.sbscrollcontainer1.scrollbarvertical1.Scrollendup1.Sbshape4.Click
Endfor
endi

if nkeycode=24  &&down arrow
For i=1 To m.n
thisform.sbscrollcontainer1.scrollbarvertical1.Scrollenddown1.Sbshape4.Click
endfor
endi
endproc