In the past I've seen this situation occur when the Notes client is starved for memory.

Dunno what the machine is telling it that is triggering this situation. I'm running Win10 and it doesn't seem to be doing this.

Base 9.0.1 or do you have FP installed?

Base 9.0.1 didn't support Windows 9.0.1 as I recall.

Drivers might also be something to look at -

Base 9.0.1 or do you have FP installed?

Base 9.0.1 didn't support Windows 9.0.1 as I recall.

Drivers might also be something to look at -

try starting process Explorer (part of SysInternals tool set by Mark Russinovich) before starting Notes.

collapse the winnt.exe part of the process tree to focus on user processes. Start Notes, and observe what is started with Notes.  Now you can see what is active when the stall occurs.  For me it was a problem with ndyncfg.exe even though DisableDynConfigClient=1 is in the Notes.ini

If it's one of the general Notes processes, Process Explorer also let's you check which threads are responsible for CPU usage.

One thing that strikes me in your statement of the problem is that all new HP notebooks are affected. Are the problems seen from the first day the staff member receives the notebook? Since the problems disappear in Basic mode, is there any improvement 

seen after renaming the workspace folder for those running in Standard mode?  If so, do the problems come back very quickly? Do the hangs follow docking or undocking of the notebooks? 

Have you tried backrevving and upgrading the video driver to see if one patch level helps?