Travel Router - Dual Band, portable?

I'm currently looking for a travel router with the below features and I'm not sure if any actually exist on the marke (which fit this criteria). I've been looking at the big name brands like tp-link and GL.Inet but I'm wondering if there are other strong competitors out there which provide the below.

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Regardless of the reasons for the below, here is the criteria.

• Small travel wifi travel router. It will need to be able to act as a small wifi repeater.
• It will need to be powered off 5 volt USB, or if possible have a built in battery.
• Needs to be Dual Band 2 & 5 GHZ
• Compact enough to carry in luggage without significant weight.
• In the future I will need to be able to utilize OpenWRT.
• If possible, I would like to connect an external yagi (antenna) of some description, or at least be able to connect an external antenna.

The two best ones I can see are the TP-Link TL-WR902AC and the GL.iNet GL-AR750S Slate . The TP-Link router does not seem to support OpenWRT but maybe there is some hack for this.

There are probably other travel routers of some obscure brands out there that I've never heard of which may be far better than the more known brands, but I'm not even sure which ones they will be.

Thought I would ask someone who does know about these things.
Any help on this would be well appreciated.

Thanks