I'm about to launch a photo cleaner app for iOS and I'm terrified of large libraries

I've been working on PicButler for the past few months. It's a photo cleaner that finds duplicates and similar photos on your iPhone, but the thing that makes it different is that it actually explains why it picks each photo as the "best" one in a group (sharpness, lighting, composition, etc). Every other app in this space just picks a winner and expects you to trust it.

The reason I built it is honestly frustration. I looked at what's out there and almost every photo cleaner charges $7.99/week (that's $416/year), uses dark patterns to trick you into subscribing, and half of them are stuffed with tracking SDKs. I wanted something I'd actually feel good about using myself. So: $4.99/month or $19.99/year, no ads, no tracking, everything processed on-device.

It's on TestFlight right now and working well on my test device (~700 photos, scan takes about 25 seconds). But here's what keeps me up at night: I have no idea how it behaves on a phone with 15,000-50,000+ photos. My detection engine uses Apple's Vision framework for similarity and perceptual hashing for exact duplicates, and I've optimized it with parallel processing and temporal pre-filtering, but there's a big difference between 700 photos and someone's 8-year camera roll.

If anyone here has a large photo library on iPhone and would be willing to give the TestFlight a spin, I'd genuinely appreciate it. Not looking for App Store reviews or anything like that, just honest feedback on whether it crashes, gets slow, or misses obvious groups.

Happy to answer any questions about the tech, the market, or why I thought competing against apps making $1M+/month was a good idea.