I've seen other companies (e.g. Stripe) also offer it via JSON, but I personally think it's not that important to provide it in a machine readable format if you don't plan on changing it; which you shouldn't as it'll break integrations. You should only add new IPs that can only be allocated to new customers.
P.S, if you'd like to start sending webhooks, you should probably check out Svix: https://www.svix.com
I've seen other companies (e.g. Stripe) also offer it via JSON, but I personally think it's not that important to provide it in a machine readable format if you don't plan on changing it; which you shouldn't as it'll break integrations. You should only add new IPs that can only be allocated to new customers.
P.S, if you'd like to start sending webhooks, you should probably check out Svix: https://www.svix.com