A shower head cannot increase pressure it can increase velocity
If you have 60 PSI at the main no matter what you other then installing a booster pump your pressure will remain the same with some friction losses
The problem with low flow shower heads is the danger of scalding when I have testified dozens of times in court
Unless your shower body has anti scald protection .
When taking a shower and someone flushes a toiler with a flushometer for example the decrease in cold water causes a severe pressure drop of the cold water and the tempered water can reach scalding temperature in less then one second
shower head manufacturer