Wheels
You can accept the DWP offer, this will lapse (cancel) your appeal, when the award is in payment then you can make a new appeal for the Daily Living component.
Just be aware, if you indicate that you will be doing this to the DWP then they will only administratively make the offer, but not put it into payment, the Tribunal may accept the DWP offer at your hearing but they are not bound by it and may decide that the current Standard Mobility award is correct.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems