Javascript; Replacing canvas objects

Hi I've noticed that in responsive projects the individual canvas objects are redrawn so I cannot modify them with Javascript (any changes are overwritten on mouseover or window resize). I can however replace the whole canvas object with my own one without seemingly running into too much trouble except the console errors thrown from Captivate trying to redraw the original Canvas. Is this a terrible idea or could it be a way to override default Captivate objects where necesary?

Cheers Jorgen