- Fixing "strict math" to resolve division ambiguities (less/less.js#1880)
- Addressing variable scope for mixin calls/definitions and callers (less/less.js#2767, less/less.js#996)
- Aligning behavior & definition of mixins and detached rulesets (less/less.js#2767, less/less.js#1859)
- Namespace referencing (less/less.js#1848), which also might relate to mixin / DR scope
- Simplifying the Less API - See api.md
Many of these are breaking changes or relate to breaking changes, hence targeting it for a full point release.