Hi Patrick & thanks for the feedback. First, glad that you enjoyed a few rounds and had a little learning curve doing so!
On the "Islands" & "4 Seasons" Boards the resources other than yellow do indeed arrive a bit late, if we rework the boards that's definitely a top priority to make all boards enjoyable - trying out "Random", "Horizontal" or "Vertical" definitely cover all the aspects of the game - and makes it harder as the enemies get buffs on different coloured tiles!
Wave 9 is already further than some of our own playthroughs, so good job on that!
The efficieny of harvesters will always be the same, as the harvesters will just skip the "empty" tiles if you build it on the border and harvest the active tiles more often!
Again - thanks for testing and GG!