Important for lvp is how flat the surface is. Otherwise, the plank will flex and the click system will fail. Engineered hardwood can be stapled down for more capability to deal with subfloor irregularities. Check it with a long level or straightedge. 6 foot should work.

Visually looks fine. You will need to go around with a lstraight edge and check for hi/lo spots and fix it,as needed.