What is Reddit's opinion of 9dBi 2.4GHz 5.8GHz Dual Band WiFi Antenna 3-Pack, Omni-Directional Wireless Antenna with RP-SMA Connector for Wireless Network Router, PCI/PCIe Card, USB Adapter, IP Camera?

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https://smile.amazon.com/dp/B07V71QK9M/

Update: I just bought a 3 pack of 9dba antennas for my TP-Link Archer C9:

https://smile.amazon.com/gp/product/B07V71QK9M

They are cheap, so it is a low cost way to see if they give me a little more range.

Does anyone know if I can use two of the antenna ports on my router for these omnidirectional antennas and the other on for a unidirectional antenna?

I am thinking if these help, and nobody says there is a problem with a router in a sun room i could use the C9 as a secondary router via an Ethernet cable to the main router. As long as the Ethernet cable doesn't touch the ground it's just the same as if it is inside the house isn't it? I read on several reddit boards not to bury Ethernet due to lightning risk.

Thank you for any advice you have.