Hello
Not that I have any intention of developing an Apple app - been there and still have bad dreams, but ...
The MDM server notes: Under IOS, an InHouse type subscription must be taken out
From what I can find on the web, the restrictions on the Enterprise/in-house distribution are as follows:
The Apple Developer Enterprise Program is only for the internal use and distribution of proprietary apps in specific use cases that are not adequately addressed with public apps on the App Store, custom apps through Apple Business Manager or Ad Hoc distribution, or beta testing through TestFlight. Your proprietary app must be developed by you for use on Apple platforms.
In addition, the following eligibility requirements apply. Your organization must:
Have 100 or more employees.
Be a legal entity. We do not accept DBAs, fictitious businesses, trade names, or branches.
Use the program only to create proprietary, in-house apps for internal use, and to distribute these apps privately and securely to employees within the organization.
Have systems in place to ensure only employees can download your internal-use apps, and to protect membership credentials and assets.
Participate in and pass Apple's verification interview and continuous evaluation process.
If these are correct then it doesn't seem possible for an independent developer to meet these criteria.
Regards
Al