Re: eBay and Amazon in V4 ?
With V4 we've included the ability to have outgoing eCommerce updates to multiple channels. So you could setup Easify to send updates to amazon, ebay, prestashop all at once. The only thing is you'd need some custom middleware (connector) to receive the outgoing messages from Easify and forward them into amazon, ebay, prestashop etc...
We intend to look into whether we can offer an Easify developed connector for eBay later in the year, but the main consideration for us is how much eBay change their API. Currently with the Wordpress/Woocommerce connector that we provide we find that Wordpress update their code base so often that it creates a support overhead for us to constantly maintain our WooCommerce connector.
Multiply that into having to maintain Amazon, Ebay etc.. etc... and we can find we spend most of our time having to keep up with other people's APIs.
So if we find that a platform (say eBay) looks to be fairly stable we can consider writing a connector for it.
Having said that, one of our partners might be able to write you a custom connector for whatever platform you want. http://www.easify.co.uk/Partners
Regards - Richard (Easify Developer)