iPhone 13 Pro Display Brightness Limited (less than 1000 nits advertised)

The question: Is it really the case that you cannot manually make the screen maxed out to 1000 nits on the iPhone 13 Pro?

The research and troubleshooting I've done (note I do not yet own the phone, just trying to figure out if it will work for what I'd like to use it for):

When I saw that the iPhone 13 Pro display had a rating of 1000 nits, I was excited to test it and went into the Apple store to check it out. I brought with me my DJI Phantom 4 Pro+ drone controller (DJI GL300E) which is also rated at 1000 nits for comparison because I want to be able to replace this device with one that uses my phone instead.

The display model of the iPhone 13 Pro was much dimmer than the DJI GL300E though. Even the salesperson helping me agreed. She checked with another employee in the tech department and confirmed that we had all the settings correct. The phone was plugged in and low power mode was turned off, true tone and night shift were off and manual brightness was enabled and set to 100%. Noticeably dimmer than the 1000 nit GL300E and no brighter than the iPhone 13 and 13 mini on display right next to it.

I just found a YouTube review of the phone and the reviewer mentioned that you can only reach 1000 nits when on auto brightness and in direct sunlight. (https://youtu.be/OyWys_OGb3g?t=230) Because the employees in the store, chat and phone support with a senior advisor were not able to confirm, I am posting here to see if that is true. Anyone have info on this?