I'm a nut CQ - not sure if I answer that question you pose - I may incriminate myself .

Kinda hard in some instances to answer the question, especially about altering the moves....I chop and change them myself when not instructing so I'll do tri dips, kick backs, french presses etc to the timing I'd do the 'normal' moves - to stay off my back (but saying that I have no issues with laying flat on the bench until 16 wks - after that point majority of health professionals say not to do it all). As I'm a VBA2C I've been asked to refrain from doing ab work - and honestly, I don't need it now, all the other exercise I do (attack, RPM, pump, walking etc) all requires braced ab's anyway....BUT - planks are totally safe throughout, until it's uncomfy - at which point you can assume the position of being on all fours and arching your back (like a cat) and releasing it, then repeat....yay, fun ab work out !

P.S - Happy Chick - keep your fluid levels up - especially as the warm weather hits.