It's here. I just figured out a slide cancel. I call it 'Launch Cancelling' dumb name or what?
So yes, it shortens your slide by 0.3-0.5s if you time it correctly which inevitably will become muscle memory. Additionally, you get a snappy boost forward if timed perfectly, AND eliminating 0.3s off your shoot + aim delay.
Disclaimer, you need to be prone for this but considering how slow mw2 is anyways, this takes 2 seconds to setup and do. Please note, shift to tac sprint must be enabled/Auto tac sprint for this to work considering timing.
HOW TO LAUNCH CANCEL:
Prone > W + Shift > Slide
(IF TIMED PERFECTLY TAP SLIDE TWICE FAST AND YOU GET THE MWIII SNAPPY BOOST)
One last thing. to make this work every time, you must only slide after your left arm lets go of your weapon and activates Tac Sprint anim.
THIS WILL TAKE SOME PRACTICE TO DO FLUENTLY.
enjoy, i know its not perfect but its just a little extra movement lol.