CPU-less equivalent of bridged config

On my CRS125 I have an SFP uplink with several vlans on it. I wish to make ether24 an access port for the vlan 300 that comes in at the SFP uplink. I’ve successfully done so by creating the vlan interface, and placing this on a bridge together with ether24:

/interface vlan print
Flags: X - disabled, R - running, S - slave
 #    NAME                    MTU ARP        VLAN-ID INTERFACE
 0 R  vlan1.300              1500 enabled        300 sfp1-master-local

/interface bridge port print
Flags: X - disabled, I - inactive, D - dynamic
 #    INTERFACE              BRIDGE              PRIORITY  PATH-COST    HORIZON
 2    vlan1.300              bridge-internet         0x80         10       none
 3    ether24-slave-local    bridge-internet         0x80         10       none

So far so good, the vlan-unaware device connected on ether24 receives an ip from the uplink.

This uplink is quite fast and therefore limited by the CRS125 cpu. I believe the above can be realized without the cpu though, only using the switch chip, but am having some trouble getting it to work. This is what I’ve tried:

# link the sfp and ether24 interfaces by making one master of the other
/interface ethernet set ether24-slave-local  master-port=sfp1-master-local

# add vlan 300 to these ports
/interface ethernet switch vlan add ports=ether24-slave-local,sfp1-master-local vlan-id=300

# allow vlan 300 traffic  -- not too sure about this one
/interface ethernet switch egress-vlan-tag add vlan-id=300 tagged-ports=ether24-slave-local,sfp1-master-local vlan-id=300

# untag on ether24
/interface ethernet switch ingress-vlan-translation add ports=ether24-slave-local new-customer-vid=300

Something’s still wrong or missing with this config, as the device connected on ether24 doesn’t get an ip from the uplink. Anybody see what’s wrong?