Proper Workflow for Client Applications

What is an ideal workflow for building mobile applications for an individual client with specific regard for the developer accounts?

I have tried three approaches so far.

  1. Develop the mobile application within my own iOS and playstore developer accounts, then try to transfer to the client’s account.
    The issue here has been that transferring apps invalidates developers from the small business program, which reduces the app store fees that these clients usually qualify for.
  2. Hosting in my own account, but directing profits to the client. App store doesnt allow this.
  3. Having the client set up their own individual developer account, giving me the credentials, and using their account to list the application. Here I run into constant issues with 2 factor authentication where I cannot take steps without the client being ready to send me the codes sent to their devices. I have my own developer account added as admin on the project, however it doesn’t seem like I can do much from that account, such as submit builds for testing.

It seems like this would be a common scenario, are there best practices in this regard?

It seems like adding my phone number to their trusted numbers on the accounts.

Will I run into issues using the same expo account with multiple ios/google dev accounts?