I use Bromophen, excellent capacity, but I don't keep working solution except in a full bottle and then overnight, maybe a week.
I keep stock in absolutely full 250ml bottles, dilute 1+3 for use.
As long as you are not leaving developer sitting in open trays overnight, sounds like you have a great process
3 minutes is great development time, takes patience.
The one thing difficult to pin down is how old is the bottle from Ilford.
A couple years ago when Tetenal got into trouble I decided to buy a couple extra boxes of Bromophen, small NYC shop, one had been sitting so long it had been made in England, that box was at least 15 years old.