My Rodinal (original Rodinal) instructions for APX400 @ EI320 says : 1+25 =7 mins and 1+50 =11 mins I cannot say which APX 400 this refers to but based on when I got the Rodinal this would have been around 2006/7 so it looks as if the APX referred to would be the same as yours if your APX expires in 2007.

Based on this I'd be worried about a time of 30 mins but I should add that I haven't used APX 400 in Rodinal so my info is Rodinal instructions based and NOT based on personal experience.

I hope this helps

pentaxuser