Paper to paper is good, minimal warping if any (I always pop journalling cards, tags etc. that I have double sided under the Webster's overnight and so far all have appeared flat and sturdy.
Yesterday I used it to adhere the sides of a heavy cardstock tag pocket just to test that weight of card and it is very sturdy and flat today when I glued it into the new journal.
I had put some of the mixed glues into an empty Tombow glue bottle and I find that this is working brilliantly. It extrudes more slowly than the original Tombow mono did, but I am able to get a lovely even thin layer over an item with almost never any overflow at the edges. When I did have some on the front of a piece of card I simply wiped it with a dry tissue. When dry there was absolutely no sign of it ever having been there. I am well pleased!
Note, I have added a tutorial for these embellishments - look in the header for Ink Splats