When you are reselling a company's plans and they change the plan details what is commonly done about your already sold plans. Are old accounts typically grand-fathered? (I know it probably depends) In other words, are the plans typically managed as groups or are restrictions and allowances placed on individual accounts.

As you can see I don't quite know how to ask the question.

What if a plan's description moves from 20 MBytes to 25 MBytes? I would guess that old accounts also migrate.

What if MySQL is added to a plan that originally did not include it? I would guess "no" since specific setups may be involved.

Is there a general answer or is it always "it depends?"
I'm not ready to ask my provider since I am trying to do my homework first.

I am setting up a system to track the conditions/details that each account signs up for. If all accounts are automatically updated then management will be much easier. I am thinking about placing a read-only copy of the appropriate plan-description within each account area. (Should it be in browseable space or outside public_html?)

Guidance please.

Gary