I think you are right! Internally the range is a higher precision than what is displayed (can only tint entire tiles). Maybe it would be a good idea to adjust the internal range calculation to what is displayed. What do you think?
Believe would be best to make it show the original range so other people don't get confused.
**my opinion
Or, when the range is 2.5 to show 2 tiles instead of 3.
Consistency would be good. Rounding up might be good since currently the game is on the harder side.
Elvis is pretty good, but he requires a few levels to be useful. Beaver only gets sightly better with levels while elvis goes from bad to excellent. Guaranteed 50% slow is good.
The general trend of the game is that most blue cards require a few levels to be viable and yellow cards often require many levels. That's not always the case, but it's different from white cards that are generally quite useful at level 1.