I have created a fiddle to study a bit the grid panel creation and destruction. Here is the link to the fiddle https://fiddle.sencha.com/#fiddle/fg3
The fiddle does the following: it has a button that when pressed it starts adding a grid to a tab panel, waits 2 seconds and removes it and this happens 20 times. At the end an alert pops up and that is the time you can call GC in Chrome Dev Tools Timeline and stop recording.
The grid I was using is quite simple, just 3 columns and default grid settings.

And here are the results of my investigation:
4.2.0
grid4.2.0.jpg

4.2.1
grid4.2.1.jpg

4.2.3
grid4.2.3.jpg

5.0.1
grid5.0.1.jpg

5.1.0
grid5.1.0.jpg

I needed to do this test because I am involved in a single page application built on 4.2.1 which has loads of grids that are created and destroyed all the time. After couple of hours of using that app the memory is increasing like crazy and I'm talking about hundreds of megs. We have addressed issues in the plugins that we are using but I wanted to see if there are issues in the standard grid too.

From this test I can see that some issues have been addressed in latest versions but I just wanted to ask the community how were these issues fixed in their apps. Migrating to a new framework version is not really an option at the moment.

Thanks,
Adrian