another imperial stout question

apologies on bringing up an old subject. i posted about this about a week ago. but some of my worries have yet to be eliminated. i have been reading that the fermentation for imperials is typically rather vigorous. if this is the case, and im having only small bubbles every 6 seconds or so, would re-pitching be an option at this point? most of the hops and yeast has risen to the top and while it looks like it would be bubbling away contently, it has done less than my amber which needed a blow off tube. it has been a week since the start to give you a time line. and fermentation did start two days into it. thanks for the advice if you all have any.

Bubbles are not a direct gauge of fermentation, let it sit and take a hydrometer reading in a week or so. RDWHAHB

thanks mate.