Shortening one blade has worked for hundreds of guys who have flown thousands of matches on 120 mph planes that operate in the 18-21,000 rpm range where balance is critical. When I was first shown the simple technique I thought it looked barbaric, but it was already proven to work by my mentors. Those days of buying Top Flite wood pylon props by the bag and reworking them are over. APC props don't need much attention at all in the diameters I use.
Most any technique has it's drawbacks and advantages.....you might even find that some engines that are either over or under balanced run smoother with the heavy blade phased a certain way [instead of using a balanced prop]. The bottom line is reaching an acceptable level of smoothness and there are several ways to get there that work.
I think 3/8" is excessive to hack off of one blade of a 10 inch prop...something is wrong with the balancing set up.