I wouldn’t worry so much about cross platform. Mac users will have GarageBand and if they are recording their first song ever even their first ‘good’ song, they will almost assuredly be using GarageBand. They would be way outside of the norm if they chose something else.

Same with iOS users. You can make great songs on iOS GarageBand and that’s where newbie songwriters will go if they aren’t using Apple Music Memos first, which exports into GarageBand.

So I would limit choices to PC platform if I was you.

I would NOT recommend Reaper for first timers. It has far too much tweak ability up front if your purpose is to teach assembling a good song right from the start without having to go download a bunch of instrument plugins and to decide on templates and what not.

Cakewalk is an entire package. DAW and all the plugins you need and notation editing and entry and available to anyone, rather than requiring a BIAB purchase.

I assume that your goal is affecting the largest number of potential people new to DAW use, that want to make songs on their computer but have never done that before.

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