Private app package name already in use
I got an APK from our Digital Signage vendor Poppulo (formerly known as Four Winds Interactive) and tried to upload it as a private Google Play app through the iframe in Intune. Got this error:

From reading this article Best practices for private apps, I understand package names must be globally unique which makes sense. I am guessing that some other org already uploaded the same package that I have and now they are essentially the only ones that can use it....
I definitely think this is Poppulo's fault and honestly I think it's kind of wild they don't just publish this app in the Google Play Store. Especially given they are such a big company and a very popular choice for digital signage.
Regardless, I am curious if anyone else has ran into this problem before and if there is any sort of workarounds. It's my first time deploying a custom app and I've only just now realized that Intune's Line-of-business (LOB) app mode that lets you upload APKs is not allowed on devices managed with Android Enterprise. Meaning Google Play private apps are my only method of uploading and deploying a custom APK.