I just ordered a Guardian flush mount for my iPad mini yesterday. It has a molded tube inlet for a cooling tube or fan. To keep things simple, I just bought their 12v fan for an extra $50. I probably could’ve come up with a less expensive fan solution via Amazon, but decided to just go with theirs. The package was right at $200. This is for my Glasair and I’m making the right side of the panel “modular” so I can have it re-cut as the iPads become obsolete.
FWIW, I’ve found that the case can really hamper cooling. I use a heavy duty Otterbox case on my phone in the RV-3 and it routinely overheats while running Foreflight in the summer.