Which build of windows 10 do you use? From my side, I did some implementations with windows 10 and I never Redirect appdata/local with Persona management.
Did you do some testing with UEM or App volumes writable disk?
Can you see which part takes the longest time when logging in?
Appdata/local is always problematic with slower logons in Persona.
Is it an option for you to use good old View Persistent Disks for appdata/local?
UEM and AppVolumes writable volumes may also help, but they require additional cost and setup.
FYI, AppVolumes does work however there is still a slight delay compared to not redirecting anything at all. The delay is usually around 10-20 seconds on every logon. This all started with Windows 10 and how it initializes the profiles now, different from Win7.
ymagalif is completely right, appdata\local is the cause of many delayed logon times, as this is also where everything related to web data is stored. It changed slightly in Win10 all Windows Apps are installed into appdata\local and you have to roam this folder in order to have a good user experience. Another problematic file within this is the webcache file,
As this is the database is the index of anything related to WinInet, it can grow extremely rapidly (already starting life at 32MB) and can also be the culprit for logon delays. *Disclaimer* I work for a company called Avanite Limited, a VMware partner who specialises in web data and cookie management. Have a look and see if this might be something you'd like to look at! https://avanite.com/webdatacontrol
We also redirect the appdata\local folder with Persona, but we've added some exclusions. The following folders are excluded from Persona:
AppData\Local\Microsoft\Windows\INetCache AppData\Local\Microsoft\Windows\WebCache AppData\Local\Google\Chrome\User Data\Default\Media Cache AppData\Local\Google\Chrome\User Data\PepperFlash AppData\Local\Google\Chrome\User Data\SwReporter AppData\Local\Google\Chrome\User Data\pnacl AppData\Local\Microsoft\Internet Explorer\Recovery AppData\Local\Microsoft\Office\OTeleData_*.* AppData\Roaming\VMware\Unity AppData\Local\Packages
If you use OneNote, there's also a large cache folder that can be excluded:
The downside of this exclusion is that the first time you start OneNote in a new virutal desktop, it creates a new Section "Quick Notes (n)", but it does saves you about 3 to 5 seconds during logon...