The 10# line has a measured diameter of 0.305 mm and the 12# 0.36, respectively. The gap is too large and I have found that the one-line-for-all happens to be about 0.32-0.33 mm, which is strong enough to horse a fish or bend a snagged Aberdeen hook, but not too strong to cause line management and casting issues. Right now I have to use 8# PLine CXX (0.32 mm) which is a little too stiffer than Izorline Platinum while stronger.

There is Yozuri hybrid #12 at .338mm. That is largest diameter line I would use for baitcasters unless it is for medium swimbait reel which I use #15 izorline. I like Izorline for its line management and pretty strong mostly #8 is enough for my everyday use. 

I have Yo-zuri hybrid 10#,  its measured diameter is perfect, 0.32 mm, but it is somehow not so strong and not so abrasion resistant.

 

The 12# has a measured diameter of 0.35 mm, not 0.338.