This feature is now part of Map Viewport Fit. This page stays up so old links keep working.
As of version 3.160.4, Explorer Loading Stability is no longer a separate module in the HomeRunner Toolkit. What it did, keeping the results grid steady while new listings load instead of letting the page jump, is now built into Map Viewport Fit.
If your site already had Explorer Loading Stability switched on, it now runs automatically as part of Map Viewport Fit. There is nothing to change and nothing new to turn on.
For the full write-up, see Toolkit: Property Map Display, under the “Map fit and polish” section.