choosing to/not to sleep with rohan in chapter one has no impact on friendship/rivalry - the different routes come from how you treat xem later. you get friendship points for listening to xem, showing interest in xir opinions and particularly from showing care/worry about IVI, while rivalry points come from shutting xem down, disregarding xir opinions on IVI, and being pro-scytha in your conversations. you can romance xem on either route, whatever your choices in chapter one - the only locks at the moment are at the end of chapter three, and these choices are available regardless of if you're friendly or rivals.
the update is very nearly done - it probably won't be released in the next couple of days, but I'm in the process of finishing it off and cleaning it up for release in january!
thank you sm<33 I'm glad you're enjoying the game!