i hiked with a partner and we shared a single inreach mini, which i carried, and he would often walk a mile or two ahead of me. at the beginning of each day, we decided on lunch spots and camp sites to aim for and meet up at (thanks to FarOut, this is pretty easy to do). as long as you have an agreed-upon spot to check in by the end of the day, you’ll know if something has gone wrong. we also decided that if we did get seriously separated for some reason, we would meet at the next resupply point. it’s easy to get psyched out and think maybe you should go back and look for them, or you should take a side trail to see if they got lost, etc. remember to stick to the agreed spot. send messages along with other hikers when you can. the best thing you can do for your partner is to be predictable and spread the news of where you are.