Is it possible to get ILR visa approved before the 5 year anniversary of my tier 2 visa start date?

Hi I am currently on a tier 2 visa (the start or valid from date on my passport is 30th June 2017). I understand the earliest date of application is 28 days before 30th June 2022 (5 year anniversary). I am planning to make an application in early June. I wonder if it makes sense for me to use the super-priority service (1 day decision)? Will the application be processed and grant me the ILR visa before 30th June 2022 (5 year anniversary)? Is the 28 days rules just to allow the applicant to submit an application earlier but they will still have to be granted the ILR after date of 5 year anniversary? Thanks

There is no such thing as the 28 days rule. It is simply a concession provided by the home office for all ILR applications where you can get ILR without completing the whole 5 years.

Thank you so much!