I've noticed that, when I'm away from the game for an extended period, such as being asleep overnight or if I'm at work and don't check during my breaks, there's a funny thing happening with my amethyst tree. Specifically, if I'm gone long enough for Techsaur to reach his maximum, then once I come back and load up the game, that resets the tree's clock -- and now it's precisely an hour until the next round of amethysts (and Techsaur energy) will show up.
I can sort of see why it does this, since the two timers seem to be linked, but given that one has a maximum counted in hours and the other in days, it feels like they shouldn't be -- and that I'm losing amethysts this way.
There's a second issue I was noticing today -- it looks like the timer for the plant store also only counts down when the game is running while actually in the game itself, and not while watching videos to speed things up/get rubies/reveal plants, unlike other timers (such as flasks -- and this is after the sneaky minor [?] update changing how flasks show results).
Totally looking forward to seeing how Techsaur uses that pipe Olaf is showing off to collect energy, btw!