script bug place() function

First of all - doing it in one file is an overkill and asking for trouble 😞

Upgrading a bit @Loic.Aigon suggestion - you should split your document into smaller chunks. 

You'll achieve few things:

• Quicker processing, 
• In case InDesign crashes - you won't have to start from scratch.
• And if you have access to multiple computers - you can do multitasking 😉 

As already mentioned by @brian_p_dts - you can either disable Redraw or save your document and then open it as invisible - you'll save a lot of time thanks to the fact that InDesign won't have to render / redraw screen.

Then, you can turn off Undo - which will save even more processing time and keep your file small.

And one more thing - what exactly are you doing? Because there may be a 3rd option 😉 

Are you opening the doc or keeping it hidden. Maybe try: app.enableRedraw = false;

If you are processing a 20k item long js array, you may try to slice the array and process smaller chunks. I am not saying it will solve your issue but I remember that for one project, I had a very important array of items and it took hours to complete. I created a series of sub-arrays (100 items max) and could process the same items in a couple of minutes. Worth the try.