The only problem I can see with bending picking up box's is if the canular is sat under your waistband/belt a very fine chance of disrupting delivery, but a very fine chance though...
I used to work in dog kennels, where I met some ill mannered mutts indeed, who would constantly jump up on you...
Not one of them managed to pull my canular out, not even the rather large staffi that as he jumped his back paw got caught in the tubing, pulling to ground level😱 The canualr stayed in place so did my pump clipped to my belt, however the tubing went from the 60cm length I use, and when I measured it it was 110cm in length😱 And even this didn't cause problems with delivery, but did change it as the new length was just to long caught on everything as it trailed behind me...
As to your first canular change in the morning, take your time there's no rush when I did my first canular and cartridge change it took me about an hour to accomplish😱 as I read my manual several times, the read each stage as I progressed LOL but now can do the whole lot in about 5 minutes flat...
Don't worry the more you use the pump, and the more you do canular/cartridges changes the more confidence you will gain..