Spirit Island List of Playtests page runs extremely slowly

(Bug, Closed -> Fixed, Priority: Critical, Test Status: No automated tests yet , Reported By Bad Link: Thing 3y284oe not found, )

Performance

Summary: This page is taking too long to render, and is timing out before it finishes rendering.

Eric's description of what's going on on this page:

The QL it's attempting to display is

[[Default Page Template -> Before Content]]
[[Playtest -> _instances -> _filter(Spirits Used -> _isNonEmpty) -> _sort(_desc(Playtest Date)) -> Listing View -> _bulleted]]

[[Default Page Template -> After Content]]

The Page template stuff is used by all my pages and loads promptly. There are about 1,500 Things hitting _sort, which isn't as high as the # of Feedback items, so I'm guessing it has something to do with Listing View, which is

[[Computed Name With Links]] - <i>recorded by [[Display Creator]]</i>

Computed Name With Links is

[[_showLink(""Playtest - [[Playtest Date -> ""__YYYY-MM-dd__""]]"")]] - [[Spirits Used -> _count]]p [[_if(_isNonEmpty(Adversaries Used), Adversaries Used -> Listing View -> _join(""vs. "", "", ""))]] [[_if(_isNonEmpty(Scenarios Used), ""with [[Scenarios Used -> _join("", "") ]] "")]]

and Display Creator is a global function with _apply of

Playtester Profiles -> _instances -> _filter(_equals(_creator, $_context -> _creator)) -> +$creator-profile
_if($creator-profile -> _isNonEmpty,
  $creator-profile -> _showLink($_context -> _creator -> Name),
  $_context -> _creator -> Name
)

(The Playtester Profiles filter in Display Creator looks like the most obvious culprit, but for all I know it could be the date formatting in Computed Name With Links.)