Are you doing this like me? I'm purposely just doing settlement, railroad, bos radiants and just collecting the unique quests in my log on my 2nd playthrough so I have reason to continue after level 50. I'm building up settlements and haven't progressed the MQ past Save Nick quest. My first playthrough showed me if you do all the quests and MQ quickly, once you finish them it gets really boring afterwards. i'm enjoying the game far more, the encounters seem far more interesting on the map too.

i did EVERYTHING on the first time thru... on the second time i am having some crazy fun with console commands. Nothing like god mode or anything, just building materials and experience so i dont have to go rummaging for a few light bulbs. I just want to see the other endings and make choices that i did not make the first time

That's what I'm currently doing aswell, for the exact same reasons

I have no current plans for a 2nd playthrough since I am still working on my 1st playthrough. Currently level 79 and I have basically focused on settlement building, exploring and some miscellanous quests. I have yet to meet up with Nick Valentine to continue the main quest.

I am not sure if this playthrough will be strictly vanilla or if I will install mods. If I decide to keep this current to vanilla, then my 2nd playthrough will definitely include mods.