If a bridge is securely fastened to the body of a Fender squier where the screws are vertical, will using a vibrato arm cause the strings to snap under tension? I've seen YouTube videos where some guitar players loosen the bridge and even have it floating above the guitar body?

During a string change on fender squier electric, I can't remember if i tightened the vertical screws where the bridge meets the guitar body. Should I leave the bridge secured in a fixed position or loosen the screws a little?

Guidance much appreciated in advance, Thank-you :)

P. S. I meant to say whammy bar when referring to vibrato. Apologies.