UEM has pretty decent in-built logging which can and should be used to initially troubleshoot both slow logon and application launch times. As it crops up for me relatively frequently I thought I would do a video running through some of the processes I use.
Hopefully this is of some use and gives you some idea of how to start approaching some optimisation. UEM is a great product and allows you to be very creative but it also needs a bit of attention to get the best out of it!
I’ve blogged previously on UEM, have a look at