GA4: manually sending parameters UA has such as GeographicalOverride?

the Measurement Protocol (Google Analytics 4) reference does not have information about parameters such as GeographicalOverride present in the Measurement Protocol (Universal Analytics) reference.

They appear to be 'automatically populated' as described in [GA4] Analytics dimensions and metrics.

But we like to send them manually from a backend app.

Do the UA parameters still work as event parameters in GA4 ?

We tried to send them as such, named like in UA, and they are shown in reports but as their raw GET keyword name only and they didn't appear "decoded" (regarding GeographicalOverride) in report maps and Lookerstudio filter dropdowns such as 'region'.

GeographicalOverride in particular we send Criteria ID according to Geographical IDs

I like to inform instead of following the GA4 reference and using the Measurement Protocol one can follow the network traffic Googles GA4 JS sends.

That works, I didn't decipher every key and I don't know how to add information about GA4 custom dimensions and custom metrics, but here is:

https://region1.google-analytics.com/g/collect?

v: 2					// possibly version
tid: ...				// GOOGLE_MEASUREMENT_ID
gtm: ...				// a tag manager id ?
_p: 940778691			// ?
gcs: G111				// geo data ?
gdid: dMWZhNz			// a geo id ?
cid: ...				// client id ?
ul: de					// user language
sr: 1920x1080			// screen resolution
uaa: x86				// user agent architecture
uab: 64					// user agent bitness
uafvl: Chromium;110.0.5481.178|Not%20A(Brand;24.0.0.0|Microsoft%20Edge;110.0.1587.63	// user agent feature version level
uamb: 0					// user agent ?
uam: 					// user agent ?
uap: Windows			// user agent platform
uapv: 15.0.0			// user agent platform version
uaw: 0					// user agent ?
_s: 1					// ?
sid: 1678693522			// session id
sct: 8					// ?
seg: 1					// ?
dl: ...					// data link = page url
dt: ...					// data title = page title
en: page_view			// event name
_ee: 1					// ?

I tried sending such a GET request, replacing data as neccessary and omitting unknown data, and it appeared in GA4 reports containing data previously missing such as screen resolution. (Unfortuanetly, like stated at the beginning, this isn't sufficient for me to replace the MP due to no knowledege how to send custom dimension information).

I know this is not an answer to the question but I see a > 50% likelihood of it being helpful. Google likes StackOverflow to be used according to https://developers.google.com/analytics/help?hl=en as of now.