Understanding Custom domain and Custom subdomain

Hi there, I’m really confused that how many custom domains and customs subdomains are allowed to be connected with softr app(s) within a subscription plan. I think it’s important to take into consideration before we choose a paid plan.

Let’s take Profession Plan as an example.
1 Custom domain is allowed to be connected with softr app(s).
※ Extra Custom domain is possible by extra monthly fee.

To understand clearly, here are questions.

  • Is “1 custom domain” app-level or workspace-level?
  • Does “1 custom domain” include its subdomains?
  • Is it possible that I connect 1 custom subdomain while domain is connected to other website builder?

For example, I have 5 apps in the same workspace with Profession Plan.
6 apps: appA, appB, appC, appD, appE, appF
3 custom domains: aaa.x ; bbb.x ; ccc.x
4 custom subdomains: help.aaa.x ; docs.aaa.x ; help.bbb.x ; help.ccc.x

Which cases are possible to be connected without extra fee?
(— means connect to 1 app in the same workspace)

  • appA — aaa.x
  • appB — bbb.x
  • appC — help.aaa.x
  • appD — docs.aaa.x
  • appE — help.bbb.x
  • appF — help.ccc.x

I read reference pages below but still feel confused…
1.Plans and pricing
2.Help docs