Deployed ALZ with accelerator. Next steps??

[mcdonamw-ews]

I used the ALZ accelerator to deploy my platform landing zone. Now I need to start building upon what was deployed. For example I need to create VPN connections in the VPN gateways that were deployed by the ALZ accelerator. Also I'm going to need to create additional management groups for application landing zones to support my business structure.

I'm not exactly sure how to best going about doing this.

Am I expected to now maintain and edit the accelerator code base that deployed the initial platform landing zone to add net new things within the platform ALZ? Or should I now have a separate projects that build on top of what is now considered "existing infrastructure"?

Ultimately I'm not sure what to do with this accelerator terraform code base. Is it meant to just be a deploy-once and be done with it kind of thing or are we expected to build upon it?

What do I do with the original bootstrap stuff that deployed the accelerator code? Like the Yaml document, or the initial platform-landing-zone.tfvars file that was the basis for the accelerator code? The bootstrap itself doesn't appear to be meant to be used again as far as I can tell.