Using OFFSET For Dynamic Ranges Along With SUMIFS?

Good afternoon, Gurus! Yet again, I’m not sure if I’m overthinking this, but I’ve picked my brain raw and need some help!

Please see the attached sample data. In Row 1, I’m using OFFSET() to total the values in the Columns as the range of the spreadsheet changes (i.e.: could be 500 rows could be 2,000.) Now, I’d like to use that same OFFSET() logic, but with SUMIFS based on the values in Column A:

For “Flow” (Row 2,) I want to only total the rows where Column A is blank.
For “Program” (Row3,) I want to total any rows where Column A is not blank AND the values is NOT “FF.”
For “Speed” (Row 4,) I want to total any rows where Column A is “FF.”
And for each, I want to maintain the dynamic functionality OFFSET() provides.

Can anyone help, please? Thanks in advance!

(And my apologies; I am about to leave work in a few minutes, so I may not respond/acknowledge any suggestions this evening, but I WILL be back first thing in the morning! Just don't want anyone willing to help to think they're going unappreciated; rest assured reputation is coming your way!)