I have used the in-game reporting function but it is very unsatisfying and it produces no confidence that a player's bug report was sent or that it would have a chance of being actioned. Your replies, on the other hand, give 100% confidence :)
I did turn the monthly pop-ups off, but the lag spikes still happened, especially as you progress further in a game session. I would glance at the date and not do anything if the date was the 28th or later lest I inadvertently end up at an extreme edge or corner of the map when the lag spike stopped.
Thanks for the replies :) Enjoy the game, even with the current bugs, and understand the game is in development. No panic on my part :)