net.pf.request_maxcount: UNDESIRABLE_OID

[Chris]

We've been developing an appliance/server based on FreeBSD &&
pf(4). We started some time ago, and have been using a very
early version of 12. We're now collecting some 20,000,000
IP's /mos. So we're satisfied we're close to releasing. As
such, we needed to bring the release up to a supported
(freebsd) version (12-STABLE). We would have done so sooner.
But we need a stable (unchanging) testbed to evaluate what
we're working on.
We built and deployed a copy of 12-STABLE @r363918 that
contained our work with pf(4). Booting into it failed
unexpectedly with: cannot define table nets: too many
elements. Consider increasing net.pf.request_maxcount.
pfctl: Syntax error in config file: pf rules not loaded
OK this didn't happen on our testbed prior to the upgrade
with a combined count of ~97,000,900 IPs. In fact the OID
mentioned didn't exist.
For reference; our testbed provides DNS, www, mail for
~60 domains/hosts, as well as our pf(4) testing. We can
happily load our tables, and run these services w/8Gb
RAM.
This OID is more a problem than a savior. Why not simply
return ENOMEM? Isn't that what it used to do? pf.conf(5)
already facilitates thresholds, and they aren't _read
only_. Is there any way to turn this OID off; like using
a -1 value? Or will we need to simply back out the commit?

Thanks in advance for any advice.

--Chris