Well it depends, the request is "fire and forget" so it's really cheap, you don't care about it coming back (or even about it generating an error — though you definitely need to handle that if you hook into ajaxError[0] or you might get recursive reporting errors). And you could expect those errors to be rare enough that the "buffer" would fill slowly and the odd error push wouldn't be a big strain.

[0] hooking into ajaxError is pretty dangerous really, if the user's connection goes down for instance the user machine is instantly going to loop at high speed.