Not sure a 440 lb load is quite right for a halyard. You may put 440 lbs on it in the initial pullup, but what happens when you have a 30 knot breeze? that 4" stretch now becomes something more.
I have xls-extra thru out. I actually prefer it over staset. It does not soak up water like staset or equal seems to do. Not that the line I use does not soak up water either, but less so. ALong with IIRC about 1/10 the stretch. For halyards I feel this is a better way to go, even for casual cruisers, as you will not have to fiddle with them as much. Sheets, in puffs, they will stretch more, giving you a bit of slack could be good.......then again, it could cause a bit more heeling due to sail shape loss.
In the end, it depends upon "your" performance expectations. For the little extra in cost, smaller lines for the strength equal, I like the xls extra. I have found I have fewer tangle issues with lines a bit smaller, vs larger diam lines like staset needs. If wearing gloves, I have not had any handling issues with smaller lines either.
A lot of this is personal in how we sail etc. Granted I do race a bit. Wat I also like about the xlsextra, is the definite color choices, I use red/blue tracer for jib lines, green/blue for spin gear, and cream/blue for main sail. I do have some lessor stretch lines, but again, try to keep the colors appropriate for the sail at hand. Also makes it easier for newbies, if they do not know where the jib sheet is, grab the "red line!" works real well!
She drives me boat,
I drives me dinghy!