Don't sweat it mate, FT psycology works in your favour here. Courses are set out by FT shooters who will be damn careful NOT to put a target out closer than 8 yards, they'll probably carefully measure it to make sure so you are virtually guaranteed an 8 yarder if it's blurred!
I was going to get a 50 foot adapter but to be honest I haven't found the need, if it's blurred but I can see some detail just not well, it's probably 9 yards. If it's very blurred I assume 8 yards, I generally get my close ones.
You don't really get enough short ones to be an issue though, some people don't dial at all just drop the mag & aim high, atleast you won't fall into the 'Turret Out' trap!