Does difficulty affect Keywarden spawn chance?

Question

Does the spawn chance of the keywardens in acts 1-4 depend on the difficulty, e.g. they spawn only if difficulty >= Torment I? Additionally, does a higher difficulty yield higher spawn chances? If so, what are the chances in numbers?

Answer 1

Keywardens always spawn in the appropriate regions if game difficulty is set to Torment I or above. The only chance that is effected by difficulty is the infernal machine drop rate. I could however not find any reliable source on actual numbers for drop rate per torment level.

Answer 2

From what I have read, this seems to be the only piece of information I could find. It states that, while being a Torment only event, the rates to drop do increase when on a higher difficulty:

Key drop odds per difficulty level:
Torment I: 25%
Torment II: 28%
Torment III: 33%
Torment IV: 38%
Torment V: 43%
Torment VI: 50%

EDIT: Also, this is what I've found regarding the later Torment Tiers:

Torment 7: +1900% EXP, 5% chance of 2 DBs per Elite*, 5% chance for 2 Rift Keys per Guardian, 3 Horadric Cache materials, 60% chance of 1 machine from KWs, 50% chance of 2 Organs per Uber.
Torment 8: +2300% EXP, 10% chance of 2 DBs per Elite*, 15% chance of 2 Rift Keys per Guardian, 3 Horadric Cache materials, 70% chance of 1 machine from KWs, 90% chance of 2 organs per Uber.
Torment 9:+2750% EXP, 20% chance of 2 DBs per Elite*, 25% chance of 2 Rift Keys per Guardian, 4 Horadric Cache materials, 80% chance of 1 machine from KWs / 10% chance of 2 machines from KWs, 50% chance of 3 organs per Uber.
Torment 10:+3300% EXP, 33% chance of 2 DBs per Elite, 50% chance of 2 Rift Keys per Guardian, 4 Horadric Cache materials, chance for bonus Cache legs**, 90% chance of 1 machine from KWs / 33% chance of 2 machines from KWs, 90% chance of 3 organs per Uber.