Two remaining things I want to improve before redeploying:

1. Occasionaly, only a crumb is dispensed.
   
   Adding a ~2200uF to the 555 output that controls the dispensing motor will keep the motor on for a fraction of a second longer after the first dispensed object is detected, decreasing the chance of just a crumb being dispensed. 
   
   UPDATE: Not doing this - I got better results by just adjusting the sensor sensitivity.
   
2. Due to the balcony mount, it's not easy to move and placing/orientation is limited. 
   
   I've been looking at parasol feet - the kind you fill with sand or water. They are not that expensive (~10 EUR). One of these, a ~32mm pipe and some u-bolts should make this thing more portable and positionable.
   
   UPDATE: This is a bit trickier that I thought and I'd have to buy stuff. I still want to do it, but will just mount it back on the balcony railing for now.