I use the same but doesn't it just save only one session? This one seems to have multiple sessions based on the config that you pass.

Use tmux-resurrect as well. But I might give this one a go. Depending on the type of code that I am working on, I like to use slightly different tmux layouts, and it would be nice to use the per project capabilities.

I use tmux-resurrect too. Saves just one session, but does the job for me.