It has been a long time since the last update of the Legenda theme took place.
While you keep updating XStore in order to cope with the advancement of other plugins such as Woocommerce or the main wordpress. This appears not to be the case for Legenda that it is rarely updated and only in cases of major changes.
Could you please confirm that the current latest Legenda 4.3.2 version is compatible with WordPress 5.6 and Woocommerce 4.8.0 ?
If your intent is to focus your effort on the XStore, could you please consider to develop a tool to smoothly migrating website based on the Legenda theme to XStore?
I believe that this would be fair toward Legenda users and avoid frustration considering that XStore appears to be more frequently updated and rich of features not available for the Legenda theme.