Hi Aztec,
You will not be able to get any more microbore hose on the retractable reel than it's stated capacity. Its ability to Auto-rewind is not based on the size of hose but on the amount rotations needed to wind a set length of hose back in. Replacing 1/2" hose with microbore will not affect the number of rotation it will be able to rewind.
Well said macmac, flexible placement is the key to hose reel unwinding. We often have a limited option on where to park and then need to run 2 hoses in completely different directions.
Paul Griffin,
I never worry about slight leaks as I have a custom built drip tray (matches my tank)for my hosereels to sit in , this can be emptied as needed. This saves water sloshing around the vehicle.