Hi, my best shot at something like you describe is having a diary close by and getting used to writing in it whenever I have free time. Try it!

We keep a page open on our notes app to track what alters did what

Find a way for alters to poll in on things, so you can find out who likes what and different skills. Have it be somewhere they can find it easily so they can answer it when they front. Make sure theres an option to type/write answers. From there, you can ask about pieces of schedules and stuff. See how they feel about your ideas. Think of it like planning things with friends with really spotty internet.