Hi!
No worries!
Yes that’s a good solution! You can get distance field shadows… or cascaded shadow maps…
I’m not sure if you’re right about your lightmap resolution… I’ve seen a couple of part which was obviously lacking of shadow detail… I remember one: the kitchen table… non of the items had ANY shadows! :S
Post process… well we can’t do EVERYTHING ourselves! 
I’m sure you didn’t program Unreal or the video software… neither the website…