I only recently discovered this. I always assumed an 8dbi antenna reached farther but didnt cover as much area as a 4dbi. Turns out the difference applies completely to height. A 4dbi antenna will cover more area above and below a miner but less distance. An 8dbi antenna will reach farther but will need to be pretty much in line of sight with other miners to witness or see witnesses. After POC11 it’s assumed that the UK will have all antennas theoretically capped at 4dbi so probably will make sense to have a tuned 868 4dbi antenna.