There are lots of topics with workarounds, but there is one I haven’t seen yet: make your iPad a HomeKit Hub (only works for older iOS versions) and export entities directly to the Apple Home app. It doesn’t have the informational and customizable pizzazz of HA dashboards, but it provides basic access to entity control and sensor readings via a native app, which is much faster than trying to render a JavaScript website on a 13-year-old device.
HomeKit protocol support has been around since iOS 8, so you can enable the home hub feature, but checking again the Home App wasn’t introduced until iOS 10 so unless it was backported or in the App Store, you may be out of luck. An iPad 4 would’ve worked! There have been a few legacy apps that duplicated the Home app’s functionality but even those may not install on your antique.
Some other clever hacks for using vintage browsers with modern websites include proxy-like packages such as browservice and wrp, but I haven’t tried either with home assistant. If you try one, let us know!
Thanks everyone. I’ve tried a few different things, but haven’t found a solution. I tried installing BrowserService on a Raspberry Pi, but it didn’t work either. Perhaps it’s due to a lack of experience with it. Thanks everyone, though. Perhaps someone else will come forward with a working solution.