I’m not really finding any existing methods/packages for me to use any of the self-hosted Captcha options, like say IconCaptcha, mCaptcha, or others.
My interest is in self-hosting is firstly due to speed (Google Services are slow af because $reasons) and secondly privacy/cost stuff.
Has anyone seen how this can be achievable within Concrete CMS? Preferably without writing my own package of course.
My Radio Captcha is self hosted 
and provides barely any security 
This IconCaptcha is self-hosted and could be a possible solution:
One thing I’d caution with IconCaptcha is that it doesn’t appear to be particularly accessible. The devs are aware of this, but it doesn’t look like they’ve implemented anything: Question/Feature Request: Support Web Content Accessibility Guidelines (WCAG) · Issue #19 · fabianwennink/IconCaptcha-PHP · GitHub
I’ve also seen this one, which does appear to have a text mode (and the ability to use a keyboard to answer the standard icon based test) - https://captcheck.netsyms.com/
Whilst a third-party Captcha, I will add that Cloudflare’s Turnstile is free, accessible, and meets GDRP/other compliance.
I put together an add-on for this a few weeks back and it’s been working well on the few sites I’m running it on: Captcha by Cloudflare Turnstile - Concrete CMS