You can download and use DaVinci Resolve for free. Instead, I purchased a copy for hundreds of dollars. Why? One reason was an expectation of getting support when I need it.
Today I found out that my expectation is not going to be met. Without getting too embroiled in the details, I will say that I wanted to know more - something, anything! - about the encoding option "Constant QP". There's a 4,000+ page reference manual for Resolve, but it says zilch about "Constant QP". "QP" doesn't even turn up in a search of the PDF. So I contacted Blackmagic Support.
The answer I got back defined what the letters stand for - Quantization Parameter - but included no information that would actually help me use it. Instead, I was directed to the Blackmagic Forums, a place where any moron can and does post incorrect information about Blackmagic products. To put it another way, instead of providing the needle I asked for, Support directed me to the haystack.