Edit: I wrote the below after a misread of your post, thinking you were referring only to material for scale/arpeggio practice. For other lesson material, see further down
If you’re making this stuff digitally, and sharing it digitally, there’s an easy solution:
Make a version that shows all approaches.
Copy that file a bunch of times.
In each copy, omit all except one.
Then you’ll have one for alt, one for swybrid, one for economy.
Have them ready, and then when you’re going over the stuff with your student, choose which to use based on where they’re at. If the notes themselves are tricky for them, it might overcomplicate things to have 3 different picking approaches on the same page. If the notes/left hand is comfortable for them and you’re focusing more on right hand approaches in that lesson, you can share the version that shows the comparison.
Similarly, this way if you have a student that has done a lot of alt picking but hasn’t heard of swybrid, you don’t have to open up a whole new topic just to show them a new scale.
so, for songs/riffs, I think it’s not worth having 3 different picking approaches on all sheets. I think it’s more sensible to only include whatever notation is relevant for what the student is working on. If you’re specifically making a point to compare different picking hand approaches, then it makes sense, but otherwise I think for each piece you and the student need to more or less settle on way of doing it, and then move from there.
In that respect it’s definitely more valuable for them to simply have a strong grasp of what those different picking hand approaches are, so they can choose to apply them without having to see picking notation for each note.