Export Settings for Film Festival

Okay, so this will probably be my least coherent post yet as this is an area where I am probably the least knowledgeable
We are exporting our latest short for a friends & family film screening we are doing and I want to make sure our settings are accurate
The last two shorts we shot on the BMMCC OG were colored/edited without us so we weren’t part of this final process
For reference, we are working on a Mac, and used the superscale feature on all of the clips
What is confusing me now is Rec709 vs Rec709a and really just what the settings should look like in general
I do know that the first time we exported we used h.264 which obviously caused banding and the last time we did ProRes 444
Thank you for any help, hope this made sense!
We are exporting our latest short for a friends & family film screening we are doing and I want to make sure our settings are accurate
The last two shorts we shot on the BMMCC OG were colored/edited without us so we weren’t part of this final process
For reference, we are working on a Mac, and used the superscale feature on all of the clips
What is confusing me now is Rec709 vs Rec709a and really just what the settings should look like in general
I do know that the first time we exported we used h.264 which obviously caused banding and the last time we did ProRes 444
Thank you for any help, hope this made sense!