I checked my logs on E30 (Map 3), you can run E40, maybe E50. You'll get a check engine light at some point, but you should be fine. At redline/fuel cut boost is 18.5 lbs and AFR is 11.8
You can afford to lean it out a little more.
E30 will make 20-30whp or more than pump gas. You can go at least Map 4 or even 5 on E30, there is enough headroom in the fuel system.
Problem is increasing boost that much depending on ambient temps might lead you to ignition pull, I'd start getting concerned with IAT's hitting 130+ degrees or more.
That's why I keep saying/recommending you invest in BMS WMI. You can run E30 on top of 50/50, it will make more power together than either of those alone.
You'll drop inlet temps down by 50-60 degrees and is worth 20-30whp just by doing that.
The Big Fuel Test Part 5: E85 Versus All—The Winner is Crowned!
They ran 100% methanol injection with VP C-85. 50/50 will cool better. It takes much more pure methanol to get the same BTU heat removal from the combustion chamber.
This is where you would experiment with mixtures. That's the freedom you get over premixed 50/50. If cooling is more of a concern, you can try 60/40 or 70/30 mixtures to find out which is more effective.