Hi Everyone, OP here. Just wanted to thank everyone for the interesting viewpoints and information.
Over the last 8.5 years or so I've stuck to JOBO's instructions to pre-wet and using Ilfotec HC 1:31 I've had zero issues with around 400 rolls of film developed with no streaks or uneven development, ever. So for me at least the JOBO recommendation is good!
Lately, I've been using a Rondix 35, manual rotary processing at approx 60 rpm, just because I feel like it, done about 30 rolls with it, pre-wet included, no issues as well.
JOBO say that in addition to giving more even development, pre-wet allows one to use the manufacturers times without the 15% adjustment, seems true to me.
Thanks again everyone.