Hi Paul, the uart1 is the same port that goes to the receiver, so you have to unplug the receiver to access the ISP interface. We can successfully reprogram the CG035 but we can't undo the damage caused by a bad flash from the VAST software. AOSENMA have done something to prevent people copying their code, and I think it looks for a serial in the CPU and won't work unless that is present, and every CG035 has a different one. If you backed up your configuration before you flashed it, it can be unbricked, but only if backed up first, since your code is unique to your CG035. It's a copy protection system.
The manufacturer has advised that we can write new software for the CG035 ourselves if we wish, and has confirmed that the uart1 is how they reprogram their quads as well, but they won't give us the software to fix it. It's a shame. Some others are still trying to get the software out of them. So if anyone wants to try updating their firmware, the first step should ALWAYS be to back up the existing firmware first using the ISP, then flash using the VAST software, then back up the new firmware if successful also using the ISP and save these backup files.
We're still looking for a solution for everyone. In the mean time, they are selling new boards for around $80 or so. Which might explain why they aren't too keen on helping us solve the problem since the boards are worth about $20.