Hey @eko
Older versions of Chromium had an issue with their Beacon implementation that meant they sent their payloads as text/plain
and you couldn’t attach custom content-type headers. Luckily that is no longer the case and Chrome, Edge, etc will perform a proper CORS pre-flight now and allow content-type headers to be amended on the request (See Beacon implementation fails in Chrome and Safari 12+ due to browser bugs · Issue #751 · snowplow/snowplow-javascript-tracker · GitHub).
The official JavaScript Tracker should fallback to sending POST on those older browsers (as Chrome throws exceptions when trying to use custom headers on those older versions that we catch). We also made some additional improvements to using Beacon in 2.13.0 of the JavaScript Tracker, which benefit older versions of Safari, that might be worth upgrading to if you haven’t already.
If this is the only reason for the fork, then you should be ok to upgrade, I don’t think you should see any consequences assuming you are using JS Tracker 2.13.0+ (I’d use 2.16.3 or 2.17.0 personally as they have smaller filesizes), Collector 2.1.0+ and Enrich 1.4.2+.