Hello! Noob here...
I need suggestions to get my living room theater system run at its best, that means connecting each component so as to get the best out of them.

My set-up includes:
- Shied TV (2017) [but I own also the new one: https://www.nvidia.com/en-us/shield/shield-tv/]
- Pioneer VSX 324 AV Receiver: http://techspecifications.net/audio-systems/pioneer-vsx-324-k-p/
- Optoma UHD35 (on its way...) to be mounted on the ceiling.
- Screen: Vividstorm ALR Slimline Tension 120" https://vividstormscreen.com/products/vividstorm-slimline-electric-tab-tensioned-drop-down-ceiling-mounted-ambient-light-rejecting-projection-screen?variant=34208618905740

The UHD35 replaces my good old Benq 1070, which was connected through a Benq Kit wireless FHD (WDP02) directly to the Shield and the Pioneer AV receiver.

Now, my question is: given that I am moving to 4K projection, which is the best way to connect the Shield to UHD35 and to Pioneer AV receiver?

I am planning to do away with the wireless receiver (it gives some problems every now and then even with Benq projector...) and go with wires.

Should I connect the Shield to the Projector and at the same time (with an HDMI splitter) to the Pioneer AV receiver?

Or should I simply connect the Shield to the Pioneer AV Receiver, and then this to the UHD35 projector?

My knowledge of the Pioneer AV receiver is very limited, as I never really studied it in depth...

Thanks for your suggestions!

Thanks for the reply!

I am a bit puzzled because the AV receiver specifications actually speak of "4K Ultra HD Pass-Through". That means that it does not process video but lets it through up to 4K, is that correct?

Actually, the manual says: "4K signal transfer – This may not operate properly, depending on the connected equipment." and then "4K 24p, 4K 25p and 4K 30p signals are supported." (I do not know what this means... probably the projector has different specifications on this)
Finally, the AV receiver works with "High-Speed HDMI" cables.

What actually makes me wonder is this:
Given that the UHD35 projector is not really a 4K projector but recreates 4K through pixel shifting of HD data, making it pass through an old AV receiver should not be a problem.

So, I understand the suggestion to let an HDMI splitter handle data, but it should also work letting it pass through the AV receiver... just wondering...

Thank you very much for your kind answer!
Eventually, I ended up buying the splitter.

I have one more question to make sure that I get the top out of my set-up, and it is about HDMI cables.

In the past, I used to connect the projector to the Shield via a wireless FHD kit. Now, I would prefer to go with HDMI cables.

I have read somewhere that a long HDMI cable, however, could deteriorate the signal.
Since the projector would be hanging from the ceiling, and I would need about 10 m (32 feet) HDMI cable, would it be better I place the splitter half way (I do not know if the splitter works also as a signal extender/booster)? or would it be better to place the Shield + splitter next to the projector and run an HDMI cable to the AV receiver (in this case, I would need to connect the Shield to the internet via Wi-Fi, while now I use an ethernet cable)?

The two different set-ups would look like this:

1. PROJECTOR--SPLITTER==SHIELD======================AV RECEIVER

2. PROJECTOR--------------SPLITTER======SHIELD======AV RECEIVER

Any ideas are more than welcome!
Thanks!