Development time, Rollei Retro 400S HC110 1+50?

I had checked the massvie development chart and it does not have times for Rollei Retro 400S in HC110.
I would like to use a 1+50 dilution.

There are a few suggestions here: http://photo.net/black-and-white-photo-film-processing-forum/00Vyf3

I will try HC-110 myself or perhaps Microphen stock for 9:00 as suggested by the massive dev chart as I have some Microphen packets on hand as well. Ordered 20 rolls of it (minimum order) so I have lots of room for experimentation anyways!