Good new blog!

Nice graph as well

Few comments:

1. Take this with a grain of salt, since I haven't played 25nl in a long time. I also never single tabled 25nl. My gut tells me that a 40bb/100 winrate is likely not sustainable, even one tabling. So I'd just keep that in mind.
2. Under the assumption that even if 40bb/100 isn't attainable, that a good winrate is. I would NOT worry too much about your red line. If you're killing it, just keep killing it. Only the green "total winnings" line matters.
3. On the topic of single tabling. Have you considered adding more tables? If you double the tables, you can afford to cut your winrate in half and still make the same hourly.
4. Also just in general I would try not to set winrate goals. You have no control over winrate. Just play your A game, and set volume goals instead. Set goals that you can control.

Just my two cents. Good luck at the tables!