The answer to that post is mine, and i confirm that there’s some delay on start but on a moto g 2014 that i have it is ~3 seconds which is not much. By comparison, Outlook takes more than 10 seconds to start on my iphone 5s..
I noticed that if I quit the app via the usual mechanism, it takes less than a second to load. However if I fully power cycle the device it’s closer to 5 seconds.