Hegners are reputed to be one of the best saws around
I had one but vibration was terrible but I suspect it was a well worn rogue, rather than the norm
With that being said I would say its just a matter of practice for your square corners
I said earlier I would usually use a 3 or 5 but didn't qualify it by saying thats what I use for most things, so wouldn't change for one item but a 0, 1 or 2 would be what is generally recommended
Does yours have a quick clamp for the top ? it makes blade changes much quicker