For question 1, no. The number is automatically assigned upon creation.
Further, the LACP administrative key (which is generated from the aggregation group number) is locally significant only. It doesn't need to match the group number or administrative key of the switch at the far end of the aggregated link. From the 802.1ax standard:
...there is no global significance to Key values. Similarly, the relationship between administrative and operational Keys is meaningful only in the context of the System that allocates it. When a System assigns an administrative Key to a set of Aggregation Ports, it signifies that those Aggregation Ports have the potential to aggregate together....
- 802.1AX-2020 - IEEE Standard for Local and Metropolitan Area Networks--Link Aggregation | IEEE Stand...
As long as the Juniper switches that you are connecting to follow a standards-based approach, then interoperability shouldn't be a problem.
Got it. Yeah this is just for consistency purposes so the AGG number matches up to access switches hostname number/ agg. ethernet number.
Looks like I'll have to manually adjust the AGG numbers by creating dummy AGG interfaces.
If your port-channels start at number 1 then if you're careful about the order you make the channels you could match them up 😉
Except the first aggregation port is aggr/0... 🤦🏻♂️
D'Oh!