I've done GA for BTS 8 times now (Kcon 2016, Wings Tour x2, LY Tour x5) and have experimented with different ways of phone usage nearly every time.
I was at the extended stage barricade for Kcon and I only recorded one song (granted, they only played five). On the first day I attended of Wings, I was at the main stage barricade. I recorded maybe half of 3 songs, the entire medley, and only like two full songs.
On the second day of Wings, my friend and I decided to chill at the back of the pit; I literally don't have any videos from that day because we decided to sing and dance our hearts out the entire time instead of trying to record.
At Love Yourself Tour this year, I was at the extended stage barricade for every show I went to. Before the tour, I thought to myself that I would likely choose one day to go without recording a single thing, just because I remembered how much fun I had on day 2 of Wings last year when I wasn't recording anything. In the end, I recorded at every day of LY Tour. The thing is, though, I only recorded when they came up to the extended stage (meaning I never got footage of any of the songs performed on the main stage, like Idol, I'm Fine, Singularity, Serendipity, Magic Shop, etc) - and after the first day, there were some extended stage songs that I decided I wouldn't record during anymore either (like Love, Just Dance, and Tear) because I wanted to fully immerse myself in those.
Why did I end up recording every day of LY Tour? Because, I noticed, the members DO interact with you specifically if you're recording. It's all part of fanservice! They know you're gonna die looking back on that footage later! I honestly think that I wouldn't have gotten some of the crazy footage/interactions that I did if I wasn't recording. But do I think that they necessarily enjoy looking down at a crowd of hundreds and hundreds of phones in the air? No, and even though it may be hypocritical and contradictory after everything I just said, I don't like the fact that they have to see that from us either.
But... Even if you're recording, that doesn't mean that you have to turn into a zombie during the show. Though there are a lot of people who probably end up watching the entire concert through their screens instead of their phones because they end up so focused on getting the perfect footage (and I've been guilty of this in the past, too - not at BTS, but when I used to attend pop-punk concerts and the like lol), it is absolutely possible to still be present when you're recording. I was conscious of how much time I spent looking at my screen this tour, because I told myself over and over again going into this tour that I didn't want to feel like I was just watching another performance on Youtube, I wanted to make sure I realized that I was there, living that right now. Some of my footage is overexposed at times or blurry because of this, but I don't mind.
I'm glad that I recorded as much as I did during LY Tour. I don't think it was too much or too little - I have just the right amount of footage that I can look back on, and I can still remember the times that x or y member made eye contact or whatever when I wasn't recording.
This is just my own opinion, but after doing this so many times, for me I find it's best to only record when they come up super close, and to actually not record during the songs you're most excited to see. Just as an example, Jimin is my bias and I don't have any footage of Serendipity from any of the days I went - I'm glad I don't, because every time he performed it I could fully and completely immerse myself in it. It's also why I stopped recording during the Trivias and Tear.