Okay, luckily enough I happen to have schematics for the 11 Pro Max, or we'd be out of luck figuring this one out.
Alisha (@flannelist), can you double check my reasoning and logic here?
All right, the I2C bus labelled I2C3 goes to three connectors on the board; the FCAM connector J7600, the Tele Camera Connector J7300, and the Touch Connector, J8100. The I/O address table for J8100 lists two addresses used for something called "Roswell", and the "Touch EEPROM". J8100 is specifically shown as going to the digitizer on the screen in the screen replacement guide.
Given that your panic log explicitly mentions Roswell:
[quote|format=featured]i2c3::_checkBusStatus SCL is stuck low; last write status 00010110 int shadow 01090100 xfer 00000000 fifo 00000000 for ***device roswell***[/quote]
I would say it's a pretty good bet the problem is being caused by a bad screen; specifically the digitizer on it. Of course, you haven't given us any other information about this error such as, did it start as a result of being dropped or some other damage to the phone?
In the absence of any other knowledge, I'd say you're probably in the market for a new screen. That would be what I would do if it was my phone.