...double nipping makes it longer, not bulkier.
Correct. However, if by "bulk" we also mean "voluminous", as we often do, we can also say that the "double nipping" makes it "bulkier".
...seeing your 10 URLs, I feel lost again ... 
My intention was the exact opposite ! When you will tie those knots a number of times ( a number which depends on the individual. I am very slow learning a new-to-me knot, and that is why I need to repeat it a dozen of times before I am able to get the "feeling" of it... So, if one needs about one minute for each knot, he will need about 15 minutes to tie each knot 12 times, so, for those 10 bowline-like knots, he will need 150 minutes = 2 1/2 hours to tie them all, the time he would have spent to watch a dumb movie...

), you will discover that they are but simple implementations of
a few only knotting in principles. Once these principles are understood and applied, the particular knots can be derived almost automatically. I refer to those posts/URL s/blah blah s only because they may contain some additional clarifying thoughts - but you can always just tie the knots shown there, and ignore the chattering about them ! I had spent much more time searching for, tying and trying those knots, and then taking pictures of them, so I think 2 1/2 hours is a bargain !
There are people that, although they
tie knots, they do not understand that they should
understand them - or, even worse, they do not understand that they do not understand ! So, they think that the knots I tie are but "
random" tangles, and that, in order to
learn them, they should do what they are used to do all the time : parrot a particular series of moves, to produce a "useful" final object, a knot they do not bother to question why it is tied like this and not in any different way. They are not
knot tyers, they are just
knot users. Parroting 10 more knots, on top of many other ones, is a hard task, indeed. However, learning, applying and understanding the few knotting principles that had generated those knots in the first place, reveals that, in fact, one can not be lost in the Knotland - and that all those dozens of knots, Urls about knots, blah blah about knots, and knot tyers tying and talking about knots, "
are only a pack of cards, after all". So, "
Begin at the beginning, and go on till you come to the end: then stop."