Do i have to specify confederation identifier and confederation peers in iBGP-only sub-AS routers

Hello there dear networking guys.
https://imgur.com/a/1z895yk

This is the topology i work on it, currently try to understand BGP confederations.

I'm not specifying the BGP confederation identifier and confederation peers on A1 router, which is iBGP-only intra-subAS router. And everything seems working for now.

I only executed these command on A1 :

router bgp 65001

network 172.16.2.2 mask 255.255.255.255

network 192.168.10.0

neighbor 192.168.10.1 remote-as 65001

Can you say that: no, these commands are not enough for healthy situation, you should specify confederation-related command on A1 also? Why would you say that?

One little question, if I add one more confederation (65003) to the topology and that confederation is connected only 65001, not physically or logically connected to 65002.
Do i have to still specify non-connected sub-AS number 65002 in bgp confederation peers 65001 65002 command or bgp confederation peers 65001 command would be enoguh, and vice versa for 65003?

Thanks a lot, have a good weekend.