Oh that's a good question! I'm gonna keep things a bit generic just to cover them all. None of them have any issues with the sexuality of others, it doesn't get in the way of what they do in the bedroom.. or elsewhere if that's their thing!
Silvana - Living as a NEET she generally is at once a day even if she's by herself a well loved toy being the solution to the single's life for her. Because of this, she's not actually sure if she has a heat cycle or when it is. She's too shy to consider looking into hook-ups and doing more adventitious things of her own initiative, so if others approach and offer and she trusts them then she'll agree to it. Linn is one of the more frequent people to do this.
Ichigo - Doesn't have a Heat cycle, and due to her line of work Sex tends to be treated as a work thing, so provided they can pay she's willing to sleep with most people, that being said it's done somewhere at the club or not at all. That being said those she finds cute will get offered a discounted rate (They just might not be told about the cost until the night is up-)
Linn - The most hedonistic of the group. Place and time doesn't matter that much provided she gets something out of it. Money, Info, ect- She's also the only one who would threaten someone to do it with her and has done so in the past, course those kind of stories get around so the few times a job hasn't gone exactly as planned has lead to the reverse, not that she minds (that much) if they're good at it. She has a fetish for Nekos as well that is something I want to get more of for her in terms of commissions...
Alice - Alice most certainly has a Heat cycle, but it's rather skewered from how much time she spends working. This tends to result in irregular weekend bar jumps until she picks up a lucky guy where they just go at it for several hours straight due to how pent up she gets at these times, it's honestly a surprise she's able to make it back to their place before she pounces them. Her preference would be towards doing it behind closed doors, but I'm sure if she was desperate and pressured into doing something in a 'somewhat secluded' space she'd go for it. [Writes that down as a idea for later]
Horror Story - Probably the most traditional of them all. It's a 'Dinner first' ordeal and if someone goes wrong then they're not coming in for Coffee. She's also a size queen as well so she's relatively picky on who she actually opts to go onto a date with as well.