Am I Repeating Myself?

Probably. But it STILL needs to be said:

PLEASE, read market guidelines every time you submit.

Market guidelines...

...sometimes change;
...are almost always just a little bit different for each market;
...are sometimes VERY different than the 'standard' market guidelines;
...show the market that you have a head on your shoulders when you prove, through your properly handled submission, that you know how to follow instructions.

It is a truth, that editors become VERY leery of submitters who clearly do NOT read and follow guidelines.

Another truth is that most markets flat out reject submissions that don't follow guidelines.

It IS worth your time, because it doesn't waste MY time. I get annoyed when people waste my time.