Will 4SEO do the same thing, provide SEO URLs for my website?
4SEO does not do anything related to SEF URLs and it certainly cannot replace in any way sh404SEF.
How can I transfer the remainder of my current product support from one to the other?
We do not transfer subscription from one product to another, except when a purchase was made by mistake for a brand new subscription.
As for upgrading sites based on sh404SEF to Joomla 4, please get all the details on our dedicated blog post from August. At the time we hoped for a release of 4SEf by the end the year but that did not happen and now this is planned for the first quarter of 2022.
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