Sure...have you had a look at ALM's Akemie's Castle? Also 4-op FM, but it has a much better panel layout that explains what's going on.
Also, there's a few decent librarian/editors for the old Yamaha devices. One of the better ones, which is also FREE (100% open source) is Ctrlr...have a look at what they offer at https://ctrlr.org/ Ctrlr's panels allow you to dive into the "guts" of numerous synths, and then to control those via the DAW or via Ctrlr's panels themselves. Since many of the older rack synths are sort of out of vogue right now, they're relatively easy to snag. Plus, Ctrlr has panels for synths that otherwise would be a total annoyance to use, such as the Roland JV1010. And, if you're used to some basic coding, you can whip up your OWN panel in it, with the aid of various SYSEX tables for the synths. No, it's not as comprehensive as a paid package like MIDI Quest, but it can hold its own with the more common instruments and processors out there.