If you think about it there should really be no concern about that piece with respect to engine cooling at all. Most motorcycles and cars are configured with the radiator in front of the engine that actually dumps heat directly onto the engine block. A simple shield like this has to be better than a hot radiator in front of the engine.
i tend to over-analyze, but much of my experience is in extremes, and I apply them to my toys in the same way as a customer coming to seek out the last etching of performance from their race engine, even though I rarely (read: never) hit those extremes, I like to know how things I add/remove change (additive or reductive) over my stock baseline.
Yamaha putting the radiator on the side with an air dam well forward of heat dissipation during a stop (traffic, idling, red light, etc) allows for a considerably smaller radiator, when things get hot, they added a considerably oversized fan, that runs at a slightly higher speed, to help draw additional air through (some of my woods bikes run fans half the size, and only to supplement mud cakes), so in my eyes any impairment to air flow, means additional cooling and I was more interested in finding out if there was a marked difference in how the engine handled that. the designers have a heat delta under normal load (normal operating temperature to fan on, to overheat creates the delta), and a 10 degree difference at normal operating shrinks the delta, over time we add weight, engine works harder, generates more heat, struggles to shed heat, delta shrinks more, get into mud, delta gets smaller, fans on more often, wear and tear, eventual breakdown, and suddenly i have 11 new gray hairs to add to my collection thanks to lost sleep over nothing
all that just to say, the question was purely a datapoint more than a sky is falling concern, i certainly don't think it'd be a massive issue, but well, having spent most of my professional life analyzing data from race analytics equipment, i'm just an old dog with old tricks
