Yes you are right, the hose from the flush port to engine is thin, i overseen that.
Interesting idea and would be nice if it works as supposed and let us know and write a how to whan you do it.
I need to think about a remote flush also as the new BF350 are so big and have a soft lightweight cowling that going there is uncomfortable.
You brought me a new idea instead of the usual remote flush solution using a normal water hose and quick connectors
Chris