You need to be constantly updating your knowledge in this area. Laundry detergents and garment materials have evolved a lot in the last few decades. A lot of conventional wisdom is outdated.

You don't need to wash Hot. Detergents work in cold water now.

Cotton is often pre-shrunk but YMMV.

Personally I do not use any of these chemical additives for clothes. The best wash is unscented detergent with vinegar in the pre-wash (where liquid fabric softner goes). Vinegar does the job of deodorizing, getting rid of static, and fabric softening. You don't need a dryer sheet. I'll use spray and wash still for stains. Dish detergent for oil stains.

I stopped wearing plastic so I'm not sure what modern polyester shirts are like.

Washing cold and drying low means you'll rarely shrink something. My favorite shirts I'll hang dry.