People are using them without reporting such problems, so the obvious answer is yes, they work without creating PIOs.
You brought up the interference issue, so obviously you've thought about it. You could be extremely limited if you operate based on the premise that wifi is an interference danger. Wifi is used extensively in aircraft cockpit systems, even by the big, brand name manufacturers. It's used extensively by portable devices such as ADS-B receivers, and by commonly used aviation apps such as Foreflight. Is it possible that wifi could cause or be disrupted by interference? Yes, it's possible. It's also possible for that to happen to just about anything else in my cockpit that uses or relies on RF radiation, but I'm not going to stop using my radios just because it's possible they could be interfered with, or cause interference. As for the video you linked, I saw nothing that indicated wifi had anything to do with his problem. So again, if you have concrete information pointing to wifi as an inherent cause of harmful interference in the cockpit, we'd like to hear about it. That's something important we'd like to be aware of. But without any such information, all you have is a suspicion unsupported by fact.
We all take risks, and we all mitigate them to the maximum extent possible based on our circumstances. As I said earlier, any impact such a problem might cause will be highly dependent on the circumstances of the individual pilot, and that pilots' mitigation efforts should be prioritized accordingly. If you're flying circumstances make an autopilot an absolutely critical system with absolute minimum margin for failure, you're going to be far more selective than other pilots without those same circumstances. But if you're going to be highly selective in that regard, it's also somewhat axiomatic that such a high standard is going to limit you to the more expensive systems. It's somewhat unrealistic to expect that the most capable and hardened systems are going to cost as little or less than those that don't seem to meet that same criteria. You get what you pay for in most circumstances, and you probably shouldn't be expecting otherwise. Now as far as wishing goes, brother, we're all in the same boat. I can wish with the absolute best of them. Just ask my wife.
