I have the 4k untrafine LG dispaly for my MB 2017 but its not the best experience with several writing apps open at once. Does it make sense to also get a Mac Mini for the instant experience if im at the desk 50% of the computer time?
I have a 2017 entry-level MB and I find it works great with that monitor for mainstream office work (MS Word, Safari, PDF Expert or Adobe Acrobat DC Pro, Safari, Spark email, etc.). I did actually try a 2018 Mini, but there were problems rendering PDFs regardless of monitor, so it went back.
I have a higher spec 2017 12" MB, which I'm very happy with for coding, but I'm getting a new Mac mini for music production and video editing, and perhaps eventually for compiling larger apps.
as for writing, I've learned to use shortcuts to open and close panes to maximize the work space, so the MB is working out great.