if you can't see the whole string, double-click the divider between column headers to expand the columns to the width of the longest entry
or, just hover the cursor over an entry to show a popup of the whole thing
warp your fleet at zero to the bookmark with "insta" on the end
set your default warp distance to 89,000 meters by right-clicking the Warp to Within button (click this show/hide video)
right-click the non-insta bookmark or the nearby wormhole or beacon and select Warp Fleet (Point) (click this show/hide video)
overview right-click menus don't reflect modified warp distances in the Warp Fleet (Point) option, but they are modified
the quick check is at the top of that menu; if Warp to Within is modified, so is Warp Fleet (Point) - even though it doesn't show it
note: the insta bookmark may or may not be on-grid with the wormhole (this doesn't change the mechanics here, just clarifying)
if there's an insta bookmark on the inside as well, repeat the process with the outhole
immediately reset the default warp to within range to zero after you initiate the last modified fleet warp
check that you did #6 (this can come back to bite you)
...
you reset your default warp to within range back to zero, right? :)