If you can send a charge of over 1kW in from the alternator, then the solar shouldn't be an absolute. That ~200Wh would be replaced in less than 15 minutes of idling.
Clearly, I have no dog in this fight... you do you.
Power is power. See how much the losses are and the load / demand and accommodate charging appropriately.
All that said... I realize these things are a bargain compared to assembling one... but there's a reason. They're not a bargain; they're just inferior. Perhaps adequate - and nothing wrong with that for the price. It would cost a bit more and require more effort to assemble a good setup; and these are easy and cheap. You do you!
@chadman, I think you're good if you max the charging with a half-decent inverter connected to CCP2 and the two-AC adapter setup. Couple hundred bucks for a decent PSW inverter (not an assurance of quality, but perhaps more likely to be decent). I use this one:
https://amzn.com/B07CKBJ9KP and they make less expensive but also decent ones like this:
https://amzn.com/B07SJYR5G7 that should meet your need.