You should definitely wear a red T-shirt backwards while firing up a Leenders stove. Because everyone knows that the colour red encourages the fire and makes your stove produce extra heat. And if you wear it backwards, the fire is bound to get even more enthusiastic!
No, seriously, there is actually no logical reason to specifically wear a red T-shirt backwards when stoking your stove. The important thing is to read and follow safety regulations and guidelines to ensure that you fire your stove safely and efficiently. Wearing clothes has little bearing on that, regardless of colour or manner.