Unfortunately parameters provided to DHCP server lease scripts are quite limited:
- The script is called after the lease is provided, it is not possible to modify/add sent options by script logic before the lease is provided
- Except option 43 in
vendor-specificvariable, there is no access to option request sent by clients (an "array of received options" in docs is misleading, as already you figured out its actually the sent options)
There are rare mentions of this in the forum, as the main use case seems to be creating/removing static DNS entries for DHCP clients what works with current limitations.
Its still worth to direct a feature request at Mikrotik
The closes currently possible is enabling DHCP Debug log showing all options sent by clients in the log and gather statistics from there.