I once filed a PCT patent and then I had to give up the entry into various countries. Because I could not afford the high sum of patent fees to various countries.
I hope the PCT rule be modified slightly as the following:
If a national patent application is published 18 months after its filing date, then a PCT may be submitted anytime within the 20 years from the filing date. Also, the application may enter various countries at anytime.
On the other side, an application could be used royalty free until it is a PCT.