Either way will work. I prefer downloading and installing manually in order to limit the amount of bloatware. But if you like not having to sort through the list of drivers then Dell Update can handle that. Either way Dell Windows 11 drivers are available here now for the 9510.
Gonna do a fresh install of Windows 11. What’s the best way to get all the Dell drivers needed? Manually downloading them from here or just get the WiFi drivers if needed and install and run Dell Update application?   tyvm 
XPS 15 9510, Windows 11 drivers