Maybe indirect has less meaning (and usefulness?) on an 18, where everything is cozier both horizontally and vertically. I admit to never so much as having seen a 3-wheeler 22 in real life.
I find the intakes harder to open/close, hard to prevent bending the vents, and also food gunks them up and then they won't seal shut, and the stop tabs either get bent or broken, making knowing when they are closed impossible without bending down to look.
But none of tat is what this thread is about ...