Hi,
If you are just looking for the basic functionality, the Embedded version should be sufficient. If you later decide that some of the Custom features could be worthwhile, you can always upgrade your license to Custom.
As for support, we are happy to help as long as it’s within the support scope. The rule of thumb is that you should be able to get the same project working/debugging on the same hardware outside VisualGDB on your own. If this is the case, we can help you get it to work with VisualGDB as well. In this case, the command-line OpenOCD from Raspberry Pi was clearly working, and the one supplied with VisualGDB wasn’t, so it was 100% within the scope.
What usually causes frustration with support is when users come up with a rather complicated setup (custom board, tricky clock settings, sleep logic) and it starts triggering OpenOCD bugs, or otherwise interfering with debugging. Some users expect that we would go through the schematic and the datasheet with them, and help them find the exact hardware setting that would fix everything, and get upset when we ask them to first get it working with command-line gdb. Another common source of frustration is when users try to change many settings at once, get a cryptic error message coming from somewhere within the external SDK, and expect us to know how to fix it without knowing what exactly they have changed. As long as you can avoid these pitfalls, you will find our support reasonable and fast.