It varies depending on the Mikrotik device architecture.
On CSS devices the ports are always part of the bridge. You can either assign two or more ports as a static link aggregation group or use LACP, either active or passive. From the help pages CSS610 use L2 hash
https://help.mikrotik.com/docs/display/ ... Manual-LAG, CSS326 and CRS3xx running SwOS use L2+L3+L4 hash
https://help.mikrotik.com/docs/pages/vi ... Manual-LAG
On CRS1xx/2xx devices to use hardware supported bonding use
/interface ethernet switch trunk not
/interface bonding. You assign two or more port members of a bridge as a static link aggregation group, note LACP is not supported. From the help page
https://help.mikrotik.com/docs/pages/vi ... s-Trunking they use L2+L3 hash.
On other devices use
/interface bonding, note the members of a bond interface should not themselves be added to a parent bridge only the bond interface. The switch chip can hardware offload the bonding if supported, see
https://help.mikrotik.com/docs/display/ ... Offloading and
https://help.mikrotik.com/docs/display/ ... es-Bonding, otherwise is handled by the CPU which may limit performance.
So using a CRS109 you should not configure TrueNAS with its default method of
LACP,
loadbalance would likely be best as
roundrobin can lead to out-of-order packet delivery.