I'm not really familiar with the code. But, isn't there a way to adjust the difficulty as a function of total hashing power of your network? The lower the network hash rate, the lower the difficulty should be. The software of many cryptocurrencies usually does this automatically after a certain period of time, reassessing the target (difficulty) to meet the average total hashing power.
I will look into that. Right now the difficulty seems to be fairly easy - you can mine several hundred PHL each day with just a CPU; but its the time between blocks that is a problem because it takes too long for a transaction to become confirmed. Thanks for the advice!