Related to #34353 and #34282. When you profile start and look at the time spend in the configuration service you'll notice that it's still very slow.

Paste require('vs/base/node/startupTimers').ticks().forEach(tick => console.log(tick.name, tick.duration)) in the dev-tools-console and see that ~100ms is spend in building/merging/deduping the configuration model.

Apart from clone it also seems that a lot of time is spend in arrays#distinct which as a potential runtime of O(n2)