do you think Hyde ever clarified to Jackie that just because he thinks Brooke is hot, it doesn’t mean he wants to be with her?
Yes. My interpretation/understanding of Hyde is that he's a sex-favorable demisexual, demiromantic. See my meta Objectifying Jackie: A Comparison of Jackie’s Relationships with Kelso and Hyde with a Focus on Allosexual, Demisexual, Demiromantic, and Aromantic Character Interpretations.
Hyde finds Brooke aesthetically appealing or attractive, which doesn't necessarily mean he's sexually attracted to her. In the 1970s, the language and understanding we have have now about the asexuality and aromantic spectrums didn't exist. Nor did it exist for different kinds of attraction. Or that sexual arousal and sexual attraction aren't one and the same.
Hyde doesn't have the language we have now. Calling Brooke hot is akin to calling a painting beautiful. That doesn't mean he's sexually attracted to that painting.
The conversation might go as follows, in Hyde's room.
Jackie: Steven, if I didn't exist, would you have sex with Brooke -- if she wanted you?
Hyde: You don't exist in this totally not-a-trap question?
Jackie: Nope. I was never born.
Hyde: What? You don't exist.
Jackie: So you do want to do it with her.
Hyde: Nope, but Iike havin' sex. And I wouldn't say no to doing it with someone on the opposite side of gross.
Jackie flinches. "What does that mean?"
Hyde (serious, sincere): Jackie, listen. I've been with a lot of chicks before you, and the sex was fun, okay? But none of it made me feel anything deeper than -- just rub your hands together real fast. Your palms.
Jackie does as Hyde instructs.
Hyde: How do your hands feel?
Jackie: Hot. Tingly. A little numb, maybe.
Jackie: I still don't get it.
Hyde: No girl has ever made me willing to leave my ice cream to get her a freakin' magazine. Or cut my hair shorter. Or like being called a cutesy nickname that should make me sick. And when you and me have sex, that's all part of it, man. Way beyond hot and tingly. And sure as hell not numb.
Jackie: So you're saying sex with Brooke would be meaningless?
Hyde: That and I got no interest in doin' it with her. Why would I settle for nothin' when I got everything right here?
Jackie: Me. You mean me! [She's happy until another question rises in her mind.] Then why do you think Brooke is hot?
Hyde: Why do you think Andy Gibb is hot?
Jackie: Excuse me. That poster shows my appreciation for his music.
Jackie: Fine. Because I like how he looks and sings and his overall Andy Gibb-ness. But I wouldn't have sex with him.
Jackie shakes her head more vigorously than she's aware of.
Jackie: I'm in love with you. And I don't actually know Andy Gibb. He's a stranger, and the idea of doing it with a stranger, even one who's that foxy ... ew. [Realizing with a gasp:] And Brooke is basically a stranger to you! So you can think she's hot, but you don't love her. You love me. I'm the first girl you've ever had a deep, undying love for. A love so powerful that you'd turn the Earth backward to save my life like Superman does for Lois Lane!
Hyde, knowing to leave well enough alone despite Jackie's hyperbole, caresses the back of her hair. "So ... wanna try to turn the Earth backward?"
Jackie: Honestly, I'd prefer just to lie together on your cot for a while.
Hyde (snuggling up with her): Okay.
Joy and a sense of security flood both Jackie and Hyde in this moment. Neither wants it to end.