IMHO it's most urgent blocker. PL/SQL Support registers own data loader for .sql extension which cannot delegate to original data loader for non-Oracle connections. It prevents users to work with IDE.
PL/ SQL will not work with another RDBMS because every system has it own syntax and rules. you need to make buffer (model) that change SQL pl /SQL to MySql or microsoft sql server T-sql. in order to make it you must use patter recognition or built-in text vaulations function.