IMO, dusting for mites or lice when there are no mites or lice around is like taking an antibiotic so you don't get pneumonia. Those Frontline products are systemic. There are systemic miticides that can be used off label for chickens, but I would never choose to treat with anything unless there is actually a problem to treat. By treating when there is not an actual problem, you may be breeding a super bug that is resistant to any product you might actually NEED in the future. However, you can apply some permethrin powder, or even a bit of DE in the coop before putting the bedding down. I dust around the perimeter of my coop before laying new bedding, and wipe down the ends of the roosts, especially getting some in the crack where roost meets the wall. An other favorite spot for mites to hang out is the nest box. A very light dusting under a deep layer of bedding can be helpful.
IMO, deep composting litter in the coop and run will go a long way to eliminating mite issues. You can also use aromatic herbs in the nest boxes and in the coop/run: Lemon balm, Citronella, Oregano, Mint, Bee Balm, Garlic scapes/leaves.
Give your flock plenty of dust bathing opportunities and they will eradicate any stray parasites before you ever have a problem worth treating.