I'm sure it'll be glorious when that map and area events are fully, er, fleshed out, so to speak.
The breeding is always a nightmare when it comes to stories and narrative stuff, mostly it was just a knee jerk reaction to the whole infertility situation (which is still a valid way to deal with things!).
On that note, it could be another cost, but a daily or weekly herbal supplement to keep the protogee risk free from dangers out in the wild or otherwise may be something worth investing in. Or a magical bracelet of some kind that achieves much the same effect. For both the ward and the PC, come to think of it.
I know it's Patreon, so aggressive grapy situations are kind of on the no no, but no reason not to be prepared - unless you don't wanna be, hahaha.
As for the ward being aggressive in bed, I guess that's what I was looking at, kind of sort of? My thinking was twofold.
There are events where you push her to the brink, saying she can't masturbate without your say so, with options to punish or not on the PC's side.
My thinking is if you do this enough time, she'll come to your bedroom desperate for relief. Depending on how you react would affect her advance. If you just tease the poor thing, but she's been leveling up in stats, she is stronk and needy, taking matters into her own hands. Skill check time. Especially if you've been teasing and denying her, and /or went and turned the gal into a futa, because her sex drive is now sky high.
Which brings up the next thing, which is Player Lust. You could easily write this as a side effect due to your link/situation with a certain dark spirit, but for example, maxed out lust makes the player eager, suggestible, and vulnerable. Males want to breed stronk. Females want to breed like bun buns. Futa's want both and are likely to boink until the symptoms go away or they go blind, whichever comes first.
So keeping it at a reasonable level is important to keep the skill checks in the wild at non ridiculous values to roll. It could also be a factor is 'training' skill or work events.
Or exploration. Another hypothetical, you are off with the ward and get some drinks, but it ends up being a crazy aphrodisiac, temporarily maxing out both the PC and the Wards lust and nymphomania. It could totally be a 'failed' potion that either you or the ward drinks, with similar effect.
A lustful PC would want to take care of the problem before it becomes unbearable, which would mean either masturbation or requesting/demanding assistance. Of course, doing so without the ward getting hers, (or watching, secretly or otherwise), means her lust gets a boost, which could trigger the wards night events or walk ins.
Which brings us full circle to 'aggressive' sex from the ward when the PC is super high lust and /or nymphomania - you just go at it. If you are both futa, it's a rare example of the ward trying to outdo her master, and the master showing off for the ward.
The more you teach her to take the lead, the more comfortable she gets being assertive, which could also affect situations where you'd normally ask for relief by hand or mouth if you are too worked up.
Lastly, if there's a lot of love, lust, and nymphomania brewing (or loyalty), waking up to a bj, cunnilingus, or her riding you may be things that happen. (If you've been training her to be assertive, it may be you may be bout to be ridden.) Of course, as the master, you can always so 'no', unless you've waived that in permissions.