My suggestion would be trying to use prewet with water, and probably trying to add a stop bath after developing. It could help with issues with uneven developing. I had a problem with streaks developing RA-4 in tubes, and prewetting the paper solved the problem for me.
I currently use a stop bath due to my SR-29 Bleach, but i will be trying a pre-wet soon, i think this will fix my issue.
developer dilution with time is a concern but i believe adjusting it with gravity tests to get it within spec might suffice.
