FYI, I installed iOS9 on an iPad Air and an iPhone 6 and at first blush the Meridian app didn't crash and it appears to function normally.

I'll mess around with the devices later today to try more functions.

So far so good.

Richard
Main: 818v3, DSP7200.2x2, Prime Headphone Amp & Power Supply, Roon Nucleus+ w/Lifetime Sub., Tidal Subscription, UHD722, IP2SL-P (TCP/IP to Serial), Sony Bravia 4K TV, Intel NUC13ANHi7 Pro PC/ Win11Pro/64, iPad Air (5th gen), LinkSys MX8500 Mesh Router (X 4), LinkSys LGS116P 16 Port Switch, PS Audio Power Plant 10.
Basement: 218, DSP5200x2