If the CG water pressure isn't good enough to give you what you want with the regulator installed, then I don't think you need to throttle the CG valve at all when you remove the regulator. I'd say the pressure's already below what the regulator is trying to maintain; in this situation, the regulator has basically just become another flow restriction.
1988 Coleman Sequoia - popup (1987-2007)
2012 Roo19 - hybid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10