Netlify supports redirects and rewrites which we can use as a reverse proxy. Simply grab the matching folder for your favorite analytics service and upload it in a new Netlify project. Than start adding the domains for every project where you want to bypass adblockers.
Why Netlify? Because it's free and there is no limit on requests like on Cloudflare Pages, where you have to pay after 100K requests.

posthog.init('phc_ItMFP3E7rtBapLnS9FPapVjUpgJBYtHi76dULIIx7EX',
{
api_host: 'https://usage.example.com/ingest',
ui_host: 'https://eu.posthog.com'
}
)
https://posthog.com/docs/advanced/proxy/netlify
<script defer src="https://usage.example.com/static/files/pa.js"
id="pianjs"
data-hit-endpoint="https://usage.example.com/p/pv"
data-event-endpoint="https://usage.example.com/p/e"
data-session-endpoint="https://usage.example.com/p/s"></script>
https://docs.pirsch.io/advanced/proxy
<script
defer
src="https://usage.example.com/script.js"
data-website-id="94db1cb1-74f4-4a40-ad6c-962362670409"
data-host-url="https://usage.example.com"
></script>