Is this setup valid? Multiple items requested by multiple stations

[ming.yuan]

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In this set up I try to let all the stations to share the same requests. So i use one single constant combinator to list all requested items and amounts and send the same signal to all stations on the right side.
I want the stations to keep request the items until I have certain amount of output, when the arithmetic combinator would put a positive number to the network to stop the demand.
However it does not seem to work.
The stations are only requesting copper ore but not the other item (from py ores)
If the request is valid I should at least receive the warning saying that no provider station is found for that item.
However I do have that provider station and empty trains in depots, and receive no warning.
Is this not possible or am i doing anything wrong?

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[Optera]

Sharing requests is not supported.
With that wiring each request will prompt LTN to send as many trains as you have stops.

That station design is atrocious.
In that space you can build 2 separate stations each providing constant 6 blue belts per wagon using buffering like wagon > inserters > chests > inserters/loaders > belt for consistent throughput.