I think it's reasonable to wait a while on this update. But there's never a guarantee the next one won't have issues too... Since it was only released about a week ago, check back on this forum to see if others post problems in next couple weeks or so. If problems like yours start getting posted, the moderators should pick up on that and alert the engineering team...  
I successfully performed the usual BIOS update to 2.8.1 from within Windows 10 a few months ago. The recently available (03 May 21) 2.9.0 BIOS update will not install within Windows 10 and yields an application error in Event Viewer (Event ID: 1000 Category: 100, unknown error). Do you think something may be wrong with the Exe file itself  (corrupt?) which was downloaded from the DELL support website for my system? I have downloaded the file more than once, at different times, just in case but the result is always the same. Would you recommend going ahead and flashing the BIOS via USB drive during startup outside of Windows? I haven't seen anyone else report this issue. Maybe I'll just wait a while since the importance of updating from BIOS 2.8.1 to 2.9.0 is likely not that great.
XPS 27 7760, Windows 10, BIOS 2.9.0 won't install