There is  a new version of the Dell Update Application specific for the Windows 10, April 2018 Update. This new version just appeared in the recent days in the Dell Support website. I installed it today on the XPS 13 9360 of my daughter, it looks really great. It has immediately found out drivers updates which were not found out by the Supportassist Application. It also provides you with a  list of the installed  drivers on your PC, such that if necessary you can control manually for further updates (this is however not simple because the last update column of the Dell Support web site does not necessarily indicate a driver update. You have to look at the drivers details to know more) This new version does not start automatically on the PC, so you use it when you want it. It has a nice user interface  
I have an Alienware Laptop, a Dell Gaming Laptop and a Dell 2in1 Laptop. As regards the Dell Update Application, after I scan for driver updates, no new updates are hardly ever found. Then I search the the Dell support website with the respective Service Tag and updates are shown as available. I cannot understand why this application does not work correctly on 3 different Dell models !
Dell Update Application