After watching all seasons of The Americans I set my subtitles to 'visible from space' size and it's wonderful. Does it look stupid? Yes. Is it effortlessly easy to read the subtitles now? Also yes. I can read normal sized ones just fine, but there's absolutely a processing cost to that still. Switching to small discreet ones is like switching to a book written in a fancy font. You can read it just fine, but it's not as smooth and effortless to do so.