Hi @geogaard ,
I'm wondering if we can help understand your reason for FME Destkop vs FME Sever. FME Server and FME Desktop engines are the same so the only difference would be missing out on FME Server functionality (Automation, logging, retries, scheduling, outgoing notifications, triggered events, on-demand UI, event failure, self-monitoring, ect.) ESRI licensing and application requirements would be exactly the same. Additionally, Geodatabase SDE is supported on 64 bit FME engines with 32 bit ArcGIS Desktops and background geoprocessing. (the only exception would be custom geodatabase like ArcFM that are written with 32 bit).