Regionalised WooCommerce stores redirection to subfolder format

Long time lurker, first time poster. Sorry in advance if I have misunderstood something fundamental!
I am setting up WooCommerce (haven’t used Wordpress in years) store and plan to have different regionalised stores in different regions, for localised content, localised fulfilment and inventory management. My reading on SEO suggests that the current thought around this is in subfolders rather than as a subdomain.
I don’t think WooCommerce multi-store is the right option, which is essentially running the stores off one installation and one server location.
So I am looking at having a server in London serving and one in USA, serving everything else (with a plan to add /au in Australia etc.)
With geosteering and workers, it seems like this is possible (although I have been banging my head against the wall playing with workers). What is the right approach if I want to go the subfolder route /au, /uk? I like the loadbalancing/geosteering idea, which also provides a fallback if one region is out.
a) which is the right approach. Cloudflare loadbalancing or Cloudflare workers, or something else
b) can I serve the subfolders from different servers and still just use Let’sEncrypt
c) if a user doesn’t like how they were routed, can they override it, if I provide a direct link to the regionalised server for example, will they skip the automated routing.