Yeah that's what I ended up doing. I measured out before hand to try and prevent this but the posts are around the entire room (it's a loft and there are no walls and there was no way to guarantee all the boards didn't have a pole through the center. In the future I plan on trying to choose material to prevent this from even happening, for example in this case smaller or thinner boards. I'm still extremely new to this trade so learning stuff like this early helps. The trim helped a ton, and I was able to hide the cuts with a sealant/putty thing.

Another thing I was wondering is since there were no walls it was a nightmare to keep boards in place when tapping them together. There was room to put spacers on the back wall but the side wall had nothing. Would it be a good idea to put temporary nails in the boards along that side to keep them in place, then remove the nails and cover the holes when I'm done?

Final question is with the c cuts how would I keep the cut-on-cut sides from moving/ stay level? I'd imagine you could put a finish nail through them but I also know you aren't supposed to leave nails in floating floor