About mt4 code migrate mt5 problem

 

recently,i want migrate mt4 to mt5.


I FOUND,MT4 code migrate mt5 can be succssful 98% code.

BUT ,if a project develop by mt5 code Use mt5 new features which wanted to  migrate mt4, may by have to success 80% code.

so ,this is my idea after read migrate document,is it right?