I know this is a pretty caveman alternative, but have you considered a spreadsheet? Mine has one nice feature, it is super fast to use, at least for the old-school type frames I like, using tubes, and a fairly standard diamond-frame shape. Change a few parameters like frame size, TT length, STA, HTA, BB drop... hit Print, bring it over to the milling machine to start cutting tubes, in usually less than 5 minutes, sometimes under 1 min. If there are a lot of parameters to change it can take longer, but one of the things it does is save designs to recall later, so I can pick a saved design to start with as a template, one that shares all the main data like tube diameters, wheel sizes, dropout brand etc.
It doesn't give you a drawing at all, but I feel those are mostly of value to the customer — the FB shouldn't need one. It outputs all the things I need, like front-center, F.wheel toe clearance/overlap, R.wheel clearance at the seat tube, steering trail, and of course tube cut lengths.
I have not tried BikeCAD, so maybe it is just as fast to use as my spreadsheet. Anyone fluent in BikeCAD want to comment? Can you call up a saved design, change a few things and have everything update itself instantly, ready to start cutting tubes in 5 minutes? Maybe I'll try it, but I am somewhat poor and also just a cheap bastard by nature. Don't even own Excel, I use LibreOffice Calc (free and compatible with Excel files). BikeCAD is $500, right? If all that gets me is a pretty drawing, I can live without that.
Long boring history explaining why I don't just upload my spreadsheet here; skip unless interested:
An ex-employer had a very basic version made for them in maybe 1986-88, that I added to over the years I worked for them, making it more adaptable to different frame styles (sloping TT, bi-ovalized tubes, extended head tubes, even tandems and a stem-design tab) and I added a ton of macros, like to choose your dropout brand/model from a menu, add in your suspension travel to see the angle changes, that sort of thing.
Then in '94 I quit that place, went to work at a shop that used AutoCAD to draw frames in 2d, which was OK but too slow. It wasn't parametric, you had to draw every tube and centerline and then dimension everything yourself. Just using AutoCAD as an "electric pencil". I missed the old spreadsheet and wanted my own, so I derived all the trig functions and wrote one in Excel, from scratch, not one bit of theirs in mine (I didn't take a copy of theirs with me). This one was never really finished, but all the important (to me) functions are working. No tandems or stem design, no menus for choosing dropout brands or suspension travel, or a few other refinements that are in the old one.
I shared this one freely on forums and such for a while, around 1997-8, until my ex-employer got wind of it and threatened to sue me because mine was "too much like theirs". Duh, it's a bike frame spreadsheet, how different could it be? I don't think any such lawsuit would have had any merit, but I couldn't afford a lawyer, so I stopped sharing it.
That was over 20 years ago and the partner who threatened me has retired. The other partner is still in the biz, but he may have no problem with me sharing my half-assed partly-done spreadsheet. I could ask him, if there's anyone here who's interested. Or if anyone wants to make their own spreadsheet, I can give you my trig formulas for the cut lengths, clearances and such so you don't need to derive them from scratch.
Caveat: I am no Excel expert, nor a mathematician. I learned just enough trig and Excel to make this spreadsheet, and then I promptly forgot it all. (Use it or lose it.) The math may contain errors, though I think I did compare its output to what I got in AutoCAD — I just don't remember for sure. If there are errors they must be very small, because I have built a few frames from it and they came out as OK as I am able to discern. The partner that sent me the nasty-gram (lawsuit threat) couldn't resist razzing me over what he said was an error in mine, seemingly unaware that by doing so he admitted that mine was not a copy of theirs, weakening his case. Maybe I used a tangent somewhere instead of a sine, which are close in value for small angles, causing a tiny error, something like that. Or maybe mine is correct and theirs is the one that's wrong, wouldn't surprise me.
Mark B