I am also 185cm with 86cm inseam riding a size 58 lcr018-d for a few weeks now. I'm using a zero offset post, 120mm stem, and 20mm of spacers. I'm very comfortable on it so far, happy I didn't go with a 56. I like the long and high setup.
I am about to pull the trigger but and going back and forth between the 56 and the 58. I have a velobuild 168 in the 58 and I had to use a 90cm stem and feel a little stretched out. Looking at the geometry the LC in 58 is about the same (9mm reach difference) but higher stack (about 25mm). The 56 is kind of the opposite oddly enough with a close stack height (6mm difference higher) to the 168 but bigger difference in reach (16mm shorter)
I’m 187cm with 86cm inseam.
That said, my flexibility is kinda crap in that I cannot touch my toes. I have the gravel Planet X Tempest in L with an 100mm stem and feels good. The LC in 56 is damn near the same stack and reach. The LC in 58 is pretty much the same reach but has an 18mm higher stack.
So, for an endurance bike I’m not sure which is the right option. Open to hearing opinions.