Yes, there is

Have a look at
-i,
--increment-min and
--increment-max as described
here:
-i, --increment | | Enable mask increment mode |
--increment-min | Num | Start mask incrementing at X | --increment-min=4
--increment-max | Num | Stop mask incrementing at X | --increment-max=8
So, if you know the password is between 6-8 chars...
hashcat -m 22500 -a 3 multibit_hash.txt -i --increment-min=6 --increment-max=8 ?a?a?a?a?a?a?a?a
will only check the masks that have 6-8 chars in them

Ah OK, thanks for that. I never really understood how --increment worked and I thought it took a mask, and then made the mask
shorter as in less characters. That's what the hashcat wiki page seemed to imply at least, in the part where it talks about having an 8 character mask but the mask's length decreases. Maybe that's what happens if you use -i and --increment-max by themselves?