I got mine (top handle version) a few years ago and it came with a 45 drive link called 12 inch bar. The adjuster has enough movement so that I generally use a 44 drive link Stihl .043 chain the current variant I believe is 61pmm3. There is an eight tooth drive sprocket for 1/4 inch pitch chain. I like the nose characteristics of that chain and one can get larger radius noses including hard noses for that. It derails easier so more often have the 3/8 lp chain on it. A 72 drive link 1/4 inch pitch chain probably should be called 13 inch in my estimation. I only have used 1/4 inch pitch chain in 0.050. Chances are the .043 stuff (in 1/4) has some nice properties if the cut is not too large in diameter. My testing found the wider kerf chains cut faster with the bar buried, the tests could be done again in non frozen wood to see if results are different. The wider kerf chains must draw down the battery faster.
I would suggest the 61pmm3 in the proper length and keep the stock chain for a spare. I find the saw has horrible chip clearing properties from what would normally be called the clutch cover. I stopped using the outer disc thing on the drive sprocket and use a slightly larger circlip than the stock one to replace that thickness.