Which was marked as a duplicate of this question: Can pool miners update early and then the pool software will automatically ask its workers for new POW when necessary?
I cannot comment on this second question as I do not have enough "points". So I am opening a new more specific question.
The answer to this second question is vague and contradicts the block header documentation.
This second answer only says "This is possible because the block template which a pool sends a miner contains the block version number, which is incremented at each fork".
However reading the block header breakdown here: What is the format of a block in the Monero Blockchain?
This states that the major_version is "always 1", and that the minor_version is "now used as a voting mechanism, rather than how this particular block is built".
Is this information correct? What does it mean "a voting mechanism"? Where is the variant version actually stored in the block header? Which field is it stored in? What is the present number of this field? What number will it be after the October hardfork?