In section translation, when the edit translation button is clicked VE is loaded with a few seconds delay for first sentence. When the user advances from the section selection to sentence selection step, we can preload the resource loader module for VE in background so that the editor appear instantly to the translator.
Change 641962 had a related patch set uploaded (by Santhosh; owner: Santhosh): [mediawiki/extensions/ContentTranslation@master] SX: Preload VE modules in sentence selector step
https://gerrit.wikimedia.org/r/641962
Change 641962 merged by jenkins-bot: [mediawiki/extensions/ContentTranslation@master] SX: Preload VE modules in sentence selector step