You won't regret either. If you want good and short the sycthe is the way to go IMO.
Only thing I'm tracking shorter is ultra5 and banish BC. Both I haven't used but read plenty of conflicting reports on here and other forums about actual sound performance. Most say "they are hearing safe". And if that is true and all you are looking for, perfect. They are shorter.
If you want a can that suppresses "well" I'll call that ~5/10 db better or said another way you are able to take 3-5 shots without ringing ears you may want a slightly longer/more volume can (I.e. scythe).
(Edit: just confirmed backcountry is only shorter by 1/4" and .5oz lighter in similar configs…non braked).
Second edit: I think I recall you shooting semi enclosed in a stand of some sort. Suppressors inclosed are much louder than not. For hearing safe in a stand you may want to hedge your bets and get a bit more supressor. I still think the scythe or something longer would be ok for that.