Pro Inks: Three Questions

Hello all,

Questions: 1) Do the Pro inks (with proper, regular agitation) expire at some point?
2) If one fails to agitate regularly, is there some point past which the Pro inks can no longer be resuscitated? Weeks, months, years??

Preamble - I noticed an older thread in which Walker noted that Pro inks had been reformulated in late 2017.

                   3) Given the above, will it ruin linearizations (or some other bad result) if I mixed 2016 or early 2017 Pro inks with those made after reformulation in late 2017?

TIA,
Mark

These inks will take a long long time to expire. Like more than half a decade in reality.

Best,

Walker

What would be the symptoms of expired ink?