I received the sling today and answer my question
Yes, without dividers this sling fits K-1 with DA*300mm and TC DA 1.4x together, plus there is about 1 inch space left.
Plus it fits at the same time my Dell xps 13" laptop. Having laptop compartment is very handy for the lighter setup.
Perhaps backpack would be better for that weight with the laptop, but I prefer slings for walks and parks (not serious mountain hiking or so).
There are a few pictures, plus the comparison with Think Tank TurnStyle 10 (medium) which fits K-1 and DA*300mm tight, and with TC attached it makes it very tight and uncomfortable, but still possible.
---------- Post added 10-17-16 at 12:46 PM ----------
I'm not crazy about back side fabric. Think Tank sling has nice glossy mesh fabric, but Pacsafe back side is a hair/dust collector from the moment I opened the sling.