Home Grown Player Status

[Dundalis]

I only have just realised that the Brexit EPL 17 foreign player limit is actually purely about nationality (initially thought 0-21 HG status was excluded). Does this mean that Home Grown Status at the club/nation means nothing in England? I know there is a requirement for European competition, but this is the 15-21 home grown rather than the 0-21 home grown, which is more strict, the latter of which is basically not utilised at all if you play in England?

The rules here are convoluted, and SI have done a poor job simplifying and making it clear how these things work IMO. Took me ages to figure out what the difference is between 0-21 and 15-21 home grown status, which is not explained anywhere in the game that I can see.