Many server owners automatically ban or kick players for using VPN, however most of the cloud gaming platforms get detected as one as well, and their IPs are indeed shared between many players which can cause issues. Therefore some wish to exclude or whitelist the IP ranges and/or ASNs from their BattleMetrics triggers and custom systems.
GeForce Now provide an up-to-date list of their IP ranges here: https://ipranges.nvidiangn.net/v1/ips.
On BattleMetrics, when editing the trigger you can add a Player IP → IP Does Not Match condition for each range from above. This will prevent players playing on GeForce Now from matching the trigger.
As for your custom backend systems, you can pull the IP ranges from the API specified above and exclude them from your checks.