I have been using my old kettle to heat spare water in so that my new larger kettle is available to collect and start heat my first runnings as soon as they stop. First running into BK, old BK adds sparge water and collects second runoff, add that to main kettle. I utilize 3 vessels but Don not consider any of them to be an HLT. Others, I believe Jonathan is in these ranks or was at one point, runoff into a bucket then add everything they collect into kettle after second runoff is complet.
Edit: android really does not like the word spare/sparge