This is true. I ended up changing the soldering iron tip out for a wide one to better heat the larger solder joints.
Also true. AMAZING.
I just went and reflowed the solder on U8 and D3 joints by reheating with my soldering iron with the smallest tip I have and - IT WORKED! I'm really stoked. Thanks so much @marxman6, your work has saved my POD HD300 from landfill, which would not be right when it's otherwise working great. Also I can use it for an important track for commercial use.
To anyone else, give it a go. A steady hand and reasonable hot iron is all you need.