TimeMaster already supports starting timers without having to add a Time Entry and going through the process of selecting a Client/Project/Task, etc, even Session settings, by duplicating an older entry. It can actually be configured to do that (including starting the timer) on a single tap.
You can also configure sessions to prompt for a note immediately after stopping the timer, so you can do it on the spot and don't have to remember later.
As far as using templates for annotations (or anything else, really), TimeMaster fully supports TextExpander, a third party app that allows you to define keyboard shortcuts you can use to expand macros into full blown notes. The reason we opted to add support for it it's because we understand that users want the flexibility to use such templates not only in session notes, but all over the application and even other applications.
My recommendation to RiversEdgePM is to stop using Tasks, and instead use the Session notes to describe what you were doing when the session ended. I'll also incorporate your wish to have some sort of session note templates to our wish-list.
Lastly, I can confirm On-Core folks live in the real world and use TimeMaster to track time and do billing. We also understand that different people and industries have different methodologies to track time, do billing, etc, and that TimeMaster might not appeal to everybody. What we are definitely proud to say is that TimeMaster development since it's inception has been entirely customer-feedback driven (even the Sessions feature, which was not originally part of TimeMaster, was added due to the request of our users).
We understand that TimeMaster still has room to grow, and we encourage our users to contact us and provide feedback so we can understand their needs and make the product even better.