Guests have to be invited to individual pages though, right? So this means I still need to either invite my spouse to every single shared page (which is problematic if my spouse wants to create a new top-level shared page in my workspace), or nest all the shared stuff under a single top-level page which is annoying (and hurts navigation on mobile).

so does that mean the person you've shared it with can have access to the full workspace? I honestly don't mind paying $8/month for 2 but it seems that the only way we can both be admin immediately bring this cost to the team plan at $16/mo for two....