Agreed. Latch cube is definetly my hardest puzzle; it takes me a lot effort to solve it, sometimes more than a 7x7 - which is a relatively easy puzzle.
Note that the definition of "hard" and "easy" is subjective here, and I have no idea how to define them in an exact way.
Does
more permutations = a higher "God's number?"
For example, on the latch cube, you can (in some cases) do R3 instead of R'. This changes the number of moves without changing the number of permutations. My guess would be that the latch cube has a higher God's number even though it has less permutations than a Rubik's cube (43,125,471,270,862,848,000 compared to 43,252,003,274,489,856,000.)
--------------------------------------------------------------------
What sort of cube are you talking about?
if there are gaps in the edges/corners that other pieces are catching on, so locking up your cube, then yes that may be a good idea... however if they're not causing a problem then you'll only be adding weight to your cube, making it slower.
I like to use unmodded cubes. Just my opinion. I'm also not quite certain how this particular mod is supposed to work.
--------------------------------------------------------------------
A couple of hours later, I have another point I would like to make.
Do sliding puzzles have more permutations because you are allowed to move one piece at a time, and each piece can move in a different direction? Unlike twisty puzzles, where you have to move multiple pieces at once, based on what face they are located on.