Beams running through skylight require no alterations to roof structural.
This is the least invasive and most cost effective.
Most of Irvine home we're built with cathedral ceilings.
New skylights need to accommodate the existing beam without cutting and disturbing the structure.
Most likely, your existing rafters are spaced 16" - 24" apart.
The rafters can be left intact and the existing roof structure, remain unchanged.
Beams running through the skylight add a beautiful aesthetic, but they should be wrapped with finish wood to enhance their appearance. To accomplish this, journeyman carpentry skills are required.