I use all squiggly 6 libs, except for AdobeSpellingUI.swc which I replace by the one of squiggly 5. And it works ...
Could you please try making SpellUI.spellingConfigUrl to SpellUI.spellingConfigURL.
Utsav...trying SpellUI.spellingConfigURL makes no difference.
Has this been resolved? If not, how can I get the squiggly 5 version of AdobeSpellingUI.swc as suggested above?