Could you please elaborate on pros and cons of 2CH vs 2x1CH options
Pros of 2x 1 channel:
Redundancy, on failure you will only lose one of them.
Better heat tolerance, not sure that is so true with the A229 Plus and Pro, but you do have only half the data being written to each memory card, and it is often the memory card that fails first due to high heat.
2K at good bitrate on both cameras, although again, the A229s manage that.
HDR on both cameras, but again the A229s manage that as well.
Double the memory capacity.
Cons:
You need to press 2 lock buttons, if you are someone who uses the lock button, which is very difficult while driving. You may be able to use the voice command though, if your car is reasonably quiet.
You need two memory cards and two hardwire kits (although that is good for redundancy).
Extracting video files is a little more difficult since they are in two places if you need both channels. Most people don't normally need both though, I don't think it is often an issue.
The rear camera is a little larger than a 2 channel rear camera, although the Mini 2 is quite small, for most people this isn't an issue.
I'm sure I've missed some, but 2 channel is more convenient, and normally recommended. No really good reason not to go for 2x 1 channel, many people have that setup because it used to be impossible to get good 2 channel cameras with 2K HDR on both channels.