See T5474. See PHI98. See PHI81. Workboard triggers.
See PHI119. This may describe a race fixed by chaos reduction in T13054. PHI1128 is probably another copy of this, which suggests it's still a real bug.
See T12175. This is a different sort of race-esque thing.
See PHI208. This describes a performance issue on workboards with very large numbers of tasks.
See PHI240. This describes a usability improvement for "Move to column...".
See T10333. See T8135. See T10335. These describe improving the grouping/sorting behavior for columns.
See T11036. Subprojects should have columns, this is just somewhat involved technically.
See T12144#226172. We should suggest "Create Subproject" above "Create Milestone", and maybe put a huge warning on "Create Milestone" that requires you to answer a quiz about whether milestones are heavy, immovable blocks of stone with strictly-ordered, sequential numbers chiseled on them, or flexible cloud-like suggestions.