Non-global PTR records are still a bit troublesome on Turris. First of all, you’ll want to know how to add configuration for Knot Resolver: Knot resolver (i.e. kresd) - DNS advanced settings for Omnia and MOX [Turris wiki]
Automatic mappings get into DNS if you check the corresponding option in reForis, so it’s possible to get those just by unblocking them
policy.add(policy.suffix(policy.PASS, {todname('1.168.192.in-addr.arpa.')}))
A down-side is that it will also unblock non-existing addresses in that range, so the upstream servers then get asked those queries.
You can do the same with IPv6. There it’s a bit more difficult to write the reverse range. I usually call kdig -x full:IPv6::address and then cut it on the appropriate place (also works the same with dig).
We have WIP upstream to make combining all the rules “just work” the way most people expect, so that no config will be needed in this case, but it surely won’t arrive to Turris soon enough for you.