Push the author, eh?
I dunno, he's a bit weird, and hard to reach. Some people say that working on Lemmings DS has driven him to insanity.
The Lemmings DS size is based off a completely random guess, basically... I couldn't find any information on the size of the levels when I started the prototyping. It's a simple flick of a couple' constants to change it, it'll just break compatibility (slightly) with any existing levels, so I wanted to save it for v4 levels. (Whatever they end up to be)
There's a reason that there aren't many traps in Lemmings DS as it stands. I hate the damned traps! I hate 'em! It's time consuming to put 'em in, and to put them in the editor and test 'em.
Lemmings DS really isn't meant to fully simulate all Lemmings and ONML levels anyway... (That's why it has 'Funk', 'Rock', 'Red Hot' and 'Hardcore' instead of 'Fun', 'Tricky', 'Taxing', 'Mayhem', 'Tame', 'Crazy', 'Wild', 'Wicked' or 'Havoc')