Timing problems in loading libraries from frozen code

[rickmcgeer]

What would you like to achieve?
I'm trying to load Google's chart libraries, and I'm hitting timeouts when the page is loaded. If I wait some time, on subsequent loads it works fine. But this leads to the question of just how do I make sure that we're getting the timing right. I'm also seeing (perhaps related) the following error:
TypeError: Cannot read properties of null (reading 'halos')
at

world.halos().forEach(function (h) {
                        return h.maskBounds = world.getHaloMask();
                      });

which corresponds to the source code

$world.execCommand("open browser", { packageName: "engageLively--galyleo-dashboard", });

But the real question is how to load safely

How are you trying to achieve that

Alternative solutions
If applicable, what other solutions have you tried?

Additional Resources
Please provide links to any custom code that might be necessary to grasp your problem. Screenshots of custom component, etc. are also appreciated.

Version: Please paste the lively.next commit on which the problem occurred here (use the copy button of the Version Checker in the bottom left corner).
c725a77