Couple questions on UI and Hifiberry DAC plus pro

Hello everyone,
I couldn’t find ready answers to couple questions so your help is appreciated.
First, are there any settings that could make Volumio UI fit iPad screen perfect? In more details, I found simple opening it in Safari to result in unneeded distracting status info shown, including IP address of the Raspberry; also, browser tabs are often shown after scrolling etc. So, Volumio looks much better to me when I add it to home screen and start fullscreen. In such mode, it’s almost perfect, but the top status bar of iPad with iPad name, clock, battery level is placed above the full screen Volumio UI and the battery icon touches the gear sign and clock are too close to the stop/play icon. Is there a way to adjust height of the top bar of Volumio so that iPad status bar doesn’t interfere with it? Another option: is there a way to hide iPad’s status info for fullscreen Volumio UI?
Another question: I run Volumio 2.041 with hifiberry DAC + pro, everything seems to be fine, but I’m not sure which volume level should I set in Volumio in order to get the best sound from my system (sure, the amplifier has its own volume control). Should I set 100 % or 90 , maybe 86 ? When Raspberry was hooked to an external USB quality DAC, 100 was obviously not the best option, 86 sounded best to me. I don’t see obvious issues with hifiberry DAC + pro, but there may be something impacting the sound too.

Your display questions are really addressed at your browser not Volumio.

Have you tried monkeyproof’s IOS app?

Thanks for your answers. Unfortunately, that app is for iOS v.10, it can’t be installed without OS update to my iPad.
Concerning the usage in fullscreen browser, it’s almost what I want, just wanted to adjust the placement or top status bar slightly. I bet I’m not the only who uses iPad with Volumio so possibly someone already solved that.

Any ideas on the best volume (and maybe some other) settings for HiFiberry DAC + pro? I’m sure there are lots of people using it with Volumio…

Since it has hardware volume, you can change volume without loss of quality.

I know it sounds disappointing, but the best settings are the default one (we try to make your life easier )…

Thank you very much for your explanation!