Homemade pirns for end-feed shuttles?

Hi all,

Having noticed that the Bluster Bay mini end-feed shuttle pirns are very slightly tapered cones rather than the usual pirn shape, I can't help but wonder: does a pirn have to have the classic pirn shape to function well?

I'm looking at needing 60+ pirns to conveniently weave my current project (doubleweave with two color-gradient wefts, 30 colors in each gradient), so buying them would be pretty pricey.  I'm thinking it should be possible to do one of two things:

(1) make a paper cone similar in profile to the Bluster Bay mini EFS pirns, using an adapter to fit it to the EFS shaft if necessary; Use 140 lb textured watercolor paper so the cone has "tooth" and the yarn doesn't just slide right off.

(2) use a paper quill as a pirn, carefully building up a mound of yarn on the back end until the profile was similar to that of a conventional pirn, then wind normally.  (This is how I do Bluster Bay pirns).

I think in either of those cases there might be a little bit of trouble with the final 1/2" or so of the back end of the "pirn", but
it should work well most of the time.  I could wind the back end with waste yarn if necessary to build up a pirn shape.

Ideally, I would like to have one pirn for each of the colors I'm producing for my gradient color dyeing projects, which would mean having hundreds of pirns in short order, so this approach appeals to me both for cost and storage reasons.

Thoughts?  Has anyone tried this?