if you are doing that way then you need to have a separate Configuration of Dispatcher farm for invalidating the content. see Configure Dispatcher to Handle Multiple Domains section on https://experienceleague.adobe.com/docs/experience-manager-dispatcher/using/configuring/dispatcher-domains.html?lan...

separate docroot is not required for dispatcher configuration for multiple site. you can work with same docroot folder for all sites configuration per environment

Tt seems the configs are right. the problem is you are creating 2 different farms prod and stage with similar configuration on vhost and is always going to last farm. Normally you shouldn't use separate farms for stage and prod and it should behaves same for all environment. Different farm is only r...

Question is not clear. Do you have requirements to filter the file type while doing the upload?

Can you try with updating those values in virtualhosts section of your farm configuration as well and check if that helps.

Yes, both vhost should have those configuration. Is it still selecting the wrong farm for you?

NOTE For proper Dispatcher invalidation, make sure that requests from “127.0.0.1”, “localhost”, “.local”, “.adobeaemcloud.com”, and “.adobeaemcloud.net” are all matched and handled by a vhost configuration so the request can be served. You can do this task by global matching “*” in a catch-all vhos...

Take a look to  https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/using-data-sly-list-with-multifield-to-include-components/td-p/439165https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/component-included-by-using-data-sly-resource-in-a-page-template/m-...

Please have a look to implement url shortening in aem react spa http://experience-aem.blogspot.com/2021/10/aem-cloud-service-url-shortening-of-react-spa.html

Yes that’s correct by default there is no default maintenance window on aem cloud service configure prior to 1st September 2023. You first need to create the maintenance window for daily, weekly or monthly as explained on https://experienceleague.adobe.com/docs/experience-manager-cloud-service/conte...