Exntend font.layout accept Array of Glyphs and return a GlyphRun?

[Typogram]

Use case: How to turn on swsh only on the first character in a GlyphRun?

When I turn on swsh on a Glyph run, by default, it is of course applied to every single charcter, looks like this:

I would like to apply swsh only to the first character (or in other words, to only part of the text string in the GlyphRun), how do I achieve that?
Perhaps there is a way to create a GlyphRun using an array of Glyphs? Because I can then find all the individual Glyphs I want based on my preference on typesetting on individual letters, and manually put them together.

Proposal

Extend font.layout to accept Array of Glyphs, and layout them, return a GlyphRun object

[Typogram]

After digging into the source code, it appeared that font.layout can in fact take glyphs as params. My bad, ignore this request!
My code that worked:

  const glyphIds = [430, 113, 1, 971, 87, 560, 929, 557];
  const glyphs = glyphIds.map((glyphId) => font.getGlyph(glyphId));
  const run = font.layout(glyphs);

Result: