Hello again!
I am planning to install linoleum flooring in my kitchen, for that super retro look. The installation instructions stress that the underlayment must be as SMOOTH as possible. Any indentations or imperfections will show through the linoleum.

My underlayment is plywood, CDX (underlayment grade). It is pretty smooth... I had to fill a couple of small surface knots with wood filler, but mostly it's a good surface.

BUT! Installation instructions for the plywood specify that a 1/8" gap be left between all panels, for expansion.

Now, isn't that gap going to show through my linoleum? What can I do about that? Can I FILL the gaps with wood filler? I would think not, since that pretty much defeats the purpose they serve, right?

Is it possible that the gap they specify is meant for outdoor sheathing uses only? (the instructions stamped on every piece of plywood do not say one way or the other) Would the fact that they're indoors, in a relatively controlled climate, mean I could fill those gaps and not worry about some kind of terrible expansion ruining the whole thing?

Any advice is greatly appreciated, as always!

Cheers, james