I think that SplitterBox doesn't control the height. You can try to test this with
sp << get xml
and maybe see which values to change (if they can be changed)
![jthi_0-1648458251508.png jthi_0-1648458251508.png](https://community.jmp.com/t5/image/serverpage/image-id/41202i3406C2EFD31C1597/image-size/medium?v=v2&px=400)
Row "column" width can be adjusted with
dt << Set Row ID Width(15);
Search scripting index for DataBrowserBox for possibly more suggestions
-Jarmo