If open tactical games is food for brain and a solid ground for Improvement, then why not play wild gambits?
If you you offer your opponent a substantial advantage, then you will have a difficult task winning. Still, I do not see how playing loosing positions will slow down your improvement process. It is a canonical advice to play stronger opponents in order to improve. Playing against a stronger opponent is a loosing position.
If you play a strange gambit with a name worthy of a middle earth dwarven prince lord, then you might have problems playing Magnus Carlsen but is it really the gambit to blame?
My home work for you, dear readers, is to come up with arguments for why it is benefitial for Chess Improvement to play vanilla Openings.