Did you have the preview on? I usually switch it off when creating longer tiddlers.
OTOH: I just created on http://lipsum.com 50 paragrahs, 4797 words, 32624 bytes of Lorem Ipsum <https://www.lipsum.com/> text, changed every "lorem" to [[lorem]] and every "ipsum" to ''ipsum'' and couldn't notice any slowdowns when pasting that text into a new tiddlert on tiddlywiki.com -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to tiddlywiki+unsubscr...@googlegroups.com. To post to this group, send email to tiddlywiki@googlegroups.com. Visit this group at https://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/9291ea7b-4795-4cca-ae59-22132cd09fe6%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
