MPH has added a field in their API for a time since the last block:
I added "last_block" field at getminingandprofitsstatistics api as you requested.
It's unixtimestamp number.
Since the pool uses PPLNS, it would be smart to auto extend the interval until a block is found (or end it earlier), otherwise the user would lose all his earnings for the round.
The same applies for YIIMP-based pools as well - they also include "timesincelast" in /api/currencies, which should be used to determine whether the script should switch to next coin or not.
I dont know if this would increase profit as general working mode, you can stay mining one coin and waiting block for hours while there is other coins more profitables at that moment.
Perhaps comparing timesincelast with averagetimeforblock or something to decide if jump or not can work.