These log lines show the two deliveries I made using that one pool to the Socks Proxy.  I think the only difference is that I only have on IP address plumbed.  I'll try to add another and see if it makes a difference, but you can see here that it does alternate between the IPs in the pool.
```[
    {
        "type": "Delivery",
        "id": "87be5c9ae24a11ee8fda0292e35192cb",
        "sender": "tom@kumomta.com",
        "recipient": "tmairs2000@yahoo.ca",
        "queue": "mytenant3@yahoo.ca",
        "site": "ip-2->(mta5|mta6|mta7).am0.yahoodns.net@smtp_client",
        "size": 354,
        "response": {
            "code": 250,
            "enhanced_code": null,
            "content": "ok dirdel",
            "command": ".\r\n"
        },
        "peer_address": {
            "name": "mta5.am0.yahoodns.net.",
            "addr": "98.136.96.75"
        },
        "timestamp": 1710452028,
        "created": 1710452022,
        "num_attempts": 0,
        "bounce_classification": "Uncategorized",
        "egress_pool": "pool-3",
        "egress_source": "ip-2",
        "feedback_report": null,
        "meta": {},
        "headers": {},
        "delivery_protocol": "ESMTP",
        "reception_protocol": "ESMTP",
        "nodeid": "d17b54eb-1bc1-4aae-9391-1cc00a9c6511",
        "tls_cipher": "TLS13_AES_128_GCM_SHA256",
        "tls_protocol_version": "TLSv1_3",
        "tls_peer_subject_name": [
            "C=US",
            "ST=California",
            "L=Sunnyvale",
            "O=Oath Holdings Inc.",
            "CN=*.mail.am0.yahoodns.net"
        ]
    },
    {
        "type": "Delivery",
        "id": "8829559de24a11ee8fdb0292e35192cb",
        "sender": "tom@kumomta.com",
        "recipient": "tmairs2000@yahoo.ca",
        "queue": "mytenant3@yahoo.ca",
        "site": "ip-1->(mta5|mta6|mta7).am0.yahoodns.net@smtp_client",
        "size": 354,
        "response": {
            "code": 250,
            "enhanced_code": null,
            "content": "ok dirdel",
            "command": ".\r\n"
        },
        "peer_address": {
            "name": "mta5.am0.yahoodns.net.",
            "addr": "98.136.96.75"
        },
        "timestamp": 1710452028,
        "created": 1710452023,
        "num_attempts": 0,
        "bounce_classification": "Uncategorized",
        "egress_pool": "pool-3",
        "egress_source": "ip-1",
        "feedback_report": null,
        "meta": {},
        "headers": {},
        "delivery_protocol": "ESMTP",
        "reception_protocol": "ESMTP",
        "nodeid": "d17b54eb-1bc1-4aae-9391-1cc00a9c6511",
        "tls_cipher": "TLS13_AES_128_GCM_SHA256",
        "tls_protocol_version": "TLSv1_3",
        "tls_peer_subject_name": [
            "C=US",
            "ST=California",
            "L=Sunnyvale",
            "O=Oath Holdings Inc.",
            "CN=*.mail.am0.yahoodns.net"
        ]
    }
]```