Using the latest version of Auto Complete (Auto Complete plugin 1.0.15 - Complete tiddlers, fields and your dreams - #141 by Maurycy) with both available CodeMirror 6, I could not get it working with them.
Has anybody tested Auto Complete with CodeMirror 6 (from @BurningTreeC or @oeyoews)?
I have version the Auto Complete plugin from Evidently which works…it’s version 1.0.20
I can confirm it does not work with the CM6 plugin! I also submitted a ticket here: https://github.com/EvidentlyCube/TW5-PluginShowcase/issues/8
$:/plugins/EvidentlyCube/AutoComplete/integration-codemirror.js I just looked at the method of the autocomplete plugin that supports codemirror5. To be honest, this is very rough, because codemirror5 also supports completion, which may cause the original codemirror completion to be unavailable (such as this GitHub - Gk0Wk/TW5-CodeMirror-Enhanced: An enhanced for CodeMirror framework in TiddlyWiki, including TW5 highlight, WikiLink auto-completion, expandable hint, snippets, etc., which I haven’t tested), or two completion pop-ups to appear at the same time. Therefore, in theory, the codemirror and autocomplete plugins have the same functions in the completion pop-up window, so there may be some conflicts if used at the same time.
In fact, the function of codemirror6 in tiddlywiki is completion priority, which is also one of the most attractive features of codemirror6 in tiddlywiki. Or you can think of the codemirror6 plugin as another tiddlywiki completion plugin
I am aware of the issue and I’ll take a look when I get some spare time for this 
Hi @Maurycy … let me know if I can add something in the codemirror-6 plugin that makes it easier to integrate your autocompletions. I believe I can deactivate cm autocompletion if it isn’t wanted
Simon
Thank you both @oeyoews, @Maurycy.
While the CM6 plugin has nice features for autocompletion, the beauty and power of AutoComplete is it works not only in editor, but also in other fields like title, tag, type, …
It is also simple to add more triggers using WikiText filters. That means average TiddlyWiki users can create their own triggers. So, I am very keen to use it in all my TiddlyWiki and I am sure it has a substantial number of TiddlyWiki users.
So, it would be great to have both working. A good new is one can configure AutoComplete plugin to only work in fields and not in editor.
Hi @BurningTreeC
Thank you for all your efforts and your kind offer in the above post. It would be very helpful to allow users to switch CM6 autocompletion on/off.
This way one can have both plugins working!