TL;DR
Change on How to request new/change infrastucture guideline.
We realized current connectivity approval process is time consuming, but connectivity approval is needed to ensure service owner is aware of the connectivity request, and to ensure requester know they are responsible for the risk by requesting that access.
To simplify the process, we decided to accept approval from service owner, even it's done in offline discussion between requester and service owner. The only constraint is requester need to share the ticket to service owner (add them as request participant), and for legacy database/service, you also need to mention them in the comment section, and tell Site-Infra you already got their approval to use their service.
See How to request new/change infrastucture guideline for more detailed information.