I used to work for a start up. We did not have support engineers. All tickets went through IT which was one person and then made their ways to dev team. Management wanted to save a few dollars so they didn’t hire any support engineers. Devs were expected to handle escalations on top of their daily tasks. This lead to burn out because deadlines did not move when there were multiple escalations in the same week, which lead to many of the bright engineers leaving the company. If you value your engineer’s time, have a small team to have customer issues.