I do it and at the moment I am doing it by myself. The way I organised is that I do the requests same day if the requests were made before 14:00 otherwise I do it next day. Unless its an emergency (total malfunction, cant issue orders or print bills/dockets), then I jump to it straight away.
I start with the default database I created that usually has functions that match majority of requests. Problem with outsourcing is that none of the setups are exactly the same and everyone wants something different which means different rules, different actions, different scripts etc. Unless someone knows exactly how you made the setup or whats different about it, you are going to be getting phone calls from the person/team you outsourced it and technically that didn’t really solve your problem of getting the load off and focusing on reselling.
Another thing is that you can pay 250$ per year to SambaPOS support team for them to provide remote support for your clients if you want to focus on reselling.
The only thing I would really be interesting in improving is some sort of support ticketing software where requests can be made and I can track it and close them off once finished. If you can recommend a good one that has reporting included, let me know.