Item Drop Rate Potential

I was digging through some old threads, and found this.

We know that item drop rate potential can be obtained on legendary tier accessories, which include:

• Pendants
  
• Belts (?)
  
• Eye accessories
  
• Face accessories
  
• Earrings
  
• Rings
  

But I've never seen this potential on a belt before, even though it's considered an accessory. Can item drop rate be obtained on belts as well?


As for the question of lesser importance:

IF the calculation for drop rate is modeled the same way as EXP gained, then it should be an additive system:

ex. Base + Event + Tier3 Item = 1 + 1 + 0.2 = 2.2x drop

in which the bonuses (i.e. event) should only be affecting the Base (1x), independent of the other bonuses.

As opposed to a multiplicative system:

ex. Base * Event * Tier3 Item = (1+0) * (1+1) * (1+0.2) = 2.4x drop

I realize that there's no effective method to test additional drop rate, asides from observing certain bosses with exceptionally low rates.

Nevertheless, my question is, would two items with drop rates (ex. +10%, +10%) be better than just one item with drop rate (ex. +20%)? Seeing how 1.1 * 1.1 > 1.2, following a multiplicative pattern. Or, would two items be weighted equally as one item? Seeing how 1 + 0.1 + 0.1 = 1 + 0.2, following an additive pattern.

Any insight on this topic, including personal experiences, is appreciated.