There's no way to stop the auto trans from downshifting, so you couldn't get a chart of the full rpm range. Based on a data log of an auto trans I have seen, it lands at about 4300 rpm when upshifting from 1st to 2nd.

Trying to get a boost chart from 1st gear wouldn't be very useful because there's not enough load on the engine to get full boost, and the engine speed accelerates so quickly that the boost curve lags behind relative to engine speed a bit in 1st gear. Even 2nd gear doesn't give max boost. I've seen boost in 3rd gear reach about 0.2 psi higher than 2nd gear. Boost can even be different in the same gear depending on whether you are driving on a slightly uphill or downhill section of road, or if the wind is blowing with/against you. Less engine load gives less boost. I used 2nd gear to get my full rpm range boost data so that I could stay within speed limits. 2nd gear takes me to about 64 mph and 3rd gear takes me to over 90 mph.

The pessimist will see this behavior of turbos as missing out on extra power in the lower gears. The optimist will this as getting a bit of extra power in the higher gears where you need it more because you are at higher speeds with more aerodynamic drag and less mechanical advantage

I think the best you can get with the auto transmission is a boost curve from about 4300 rpm onward, which won't be much of a curve because boost levels out before that. You can at least use the data logs to see how much boost you're getting. Default data logging includes barometric pressure and manifold pressure. View the data log in the Data Viewer app, convert the barometric pressure reading from inHg to psi, then subtract that from the MAP reading at any point in the data log to see how much boost you had.