at this time, you may break down your project into many sessions and you won’t need to worry about losing your progress. my dog is obsessed with these! you put us in the line for the car in front, grabbed my hand when we got in it and told me we had to use all the oxygen we were allowed, had to scream until we had none left in our lungs, until we were dizzy with too much and not enough all at once. please contact and discuss your requirements. 