Update:
After running about a dozen more experiments with and without Start10 installed, I have come to the conclusion that there is no negative interaction between Start10 and Acronis True Image 2015. The issue I am experiencing is entirely associated with Acronis True Image 2015.
Original text:
My Windows 10 system runs flawlessly and file and system backups with Acronis True Image 2015 run and complete without incident. However, when I installed Start10 (which I truly would like to use) my PC becomes extremely sluggish after completing backups. An indication that something is amiss is that an icon for the Acronis True Image Monitor (TrueImageMonitor.exe) that appears in the taskbar notification area during backups remains even though the backup completes successfully.
Uninstalling Start10 returns my PC to its original performance and the icon for the Acronis True Image Monitor once again disappears after a backup is completed.
If anyone else is using Acronis True Image 2015 and Start 10 with Windows 10, I would love to know if you have or have not had a similar experience.