Something that the recent RPGs do, is they allow us to save certain points since we can’t replay missions in their games too. Since I know that the progression in Halo Infinite is complicated with the skill tree given and real-time scenarios, you won’t be able to make a proper mission-to-mission like in past Halo games.
So, just allow us to manually save at certain points in the game so we can come back to that specific moment. Though this might mean they we lose random checkpoints (where in my opinion I hate. Sometimes I get a checkpoint that I didn’t want me to be in a position in), but this allows us to properly pace our missions if we are trying to do new fun things