Use the enclosure / chassis rating, remember flexibility is to do with the number
of strands more than the overall thickness. More finer strands are more flexible.
1.2A isn't much most wire will take that. Silicone insulated wire will take more as
it stands higher temperatures without damage, but hotter wires have more resistance
so there is a limit (your wire becomes a fuse instead).
I think the power transmission ratings are assuming lots of wires bundled in the same
conduit without ventilation, so are more conservative.