Alternatives to Adobe AEM for Coversheets generation

Since the support for Adobe Experience Manager is being deprecated I’m looking at the workflows dependant on PDF publishing with AEM.

I had a look at the free trial of the WEX coversheets extension and it’s fine but I’d need to make a few changes before it would be a drop-in replacement for the coversheet generation customisation we have with AEM currently.

Has anyone found any alternatives?

At the moment AEM converts html files to PDF and merges them with a PDF of the primary content to create the PDF representation file, the primary content can be any office file. AEM does this via a SOAP webservice which you can inspect via it’s WSDL and it seems AEM has far more capabilities than Windchill actually needs so I’m wondering whether to try replacing it with a service that does the html/PDF conversion and merging with a simpler app based on plain java HttpServer and openhtmltopdf?

I ran TCPMON to capture the requests and responses between Windchill and the AEM Assembler Service and it seems Windchill is only ever calling one of three services, the WSDL, invoke or invokeOneDocument - so it should be possible to create an app that pretends to be AEM and provides the same SOAP responses?

Appreciate any thoughts