It would be nice if NPC pregnancies used Steele's Virility Speed Modifier, rather than completely ignoring it. Then using Fertite+ various other mods would speed up NPC pregnancies up to 5x or so.
Fertite+ does not increase male Speed Modifier. In fact, I don't know of any way to increase it.
Honestly, paternal bonus is currently only used for halving the absurd numbers of the maternity bonuses. Which could be done directly and be a lot more intuitive. (Incubator = 1.5x? 2000% = 10.5x?)
Even in the tutorial when you want to recruit Celise, you must have sex with her or else she'll be removed from the game.
on a more serious note, imo if you are required to have sex to progress the tutorial, that should be an indicator for what the game is going to be like; sex is going to be required for some progression. again, in a sex game
If you skip the tutorial, you can recruit Celeise without having sex with her. And while sex is required for some NPC interactions, I don't think it's ever required for the main quest.
It's entirely reasonable to want to recruit Anno or befriend Syri (and abuse her bookclub) without fucking them first. Or if you like a character, but don't have any sexual attraction to them.
It would be nice if Anno's Test Drive->Petplay counted. Especially since she hates Tarkus, You'd think she'd jump at any chance, sex with Steele or not. It's not like she goes without if you never fuck her again after recruitment.
My latest gripe: Power Armor Weapons double the time to move between squares on the map, unless Steele is wearing Power Armor. This applies whether the weapon is equipped or in the inventory.
40+ Physique, Cybernetic Exoskeleton & Bigger Guns don't count. Hoverboard cancels it out.
Power Armor also slows Steele while in the Inventory, but not while worn. Cybernetic Exoskeleton does whether it's worn or not (this is probably a bug).
This is not documented anywhere I could find.
