SliTaz proposes LXQT in an old version of Qt.
no problem that the version is old if all works correctly and if we have great choices with that (new versions have often a really reduced choice of offered adequate packages! That is actually the case with webengine that Qupzilla did choice for it's new development. And, no webengine, no spell check in (the old version of) Qupzilla! Xombrero has a very good spell check if you register the hunspell dictionaries in the ~/.xombrero.conf . But it can only check the existence of words write so as you did write in one of the registered dictionaries, if you register more than one, and not if it is good according the used language! Xombrero exists at the SliTaz scope of packages and is only a little extension for it as webkit is also yet installed for TazWeb and TazPanel!
which are the proposed Qt based applications conform to the Qt from LXQT in the actual scope of packages from SliTaz?