It's really unfortunate that Tesla don't publish this type of information. We need to rely on independent testers to gather and publish their experiences. Tesla could easily show the "theoretical max" on your charging screen. I think it's a conscious decision to not present too much information to the users.
They can change the charging curve as they wish in software updates too so don't take this as very precise information. The main piece of information is that you need a few percent charge in the battery before it rips to full speed, and it cannot sustain that speed past 40-50% charge.