How to change the size of plots inside a layout interactively?

Howdy!
Using a grid, column or row layout of plots, is there any possibility to change the size of the plots inside the grid interactively after creating with something like a splitter?
When creating the grid, there is a parameter sizing_mode, but this only sets the sizes during creating.
In the search I found some hints about a hot corner in prior versions, but I couldn’t find anything in the user guide or reference.