I am not sure if TW in its new release still support IE11 or not. But today Internet Explorer (IE) has been retired after 25 years.
Frankly my response to this question would be initially “who cares”, but the reason I ask this is because “I do care”. Anyone using such a risky and antiquated browser that does not receive updates and always was risky to start with should “stop doing it now”. If you are bound by an old computer or Operating system you best seek other browser alternatives.
I would be shocked if anyone had to use TiddlyWiki in an environment where you could only use IE.