So, yes I've read about how to get FME 64 bit to run on a machine with 32 bit ArcGIS Desktop installed, but for ease of deployment on different user PCs that will only have the standard ArcGIS configuration, I've opted for 2 workspaces:
- One to run an extraction of source data with an ArcSDE Reader executing in FME 32 bit. This is due to the dependencies of FME on the bitness of the ArcGIS install
- One to transform it by executing in FME 64 bit. The data model is very large and RAM intensive so needs to run in FME 64 bit.
FME 2018.1
The best solution I can think of it to BAT file this by calling the workspaces against the individual 32 bit and 64 bit FME executable file paths, because I don't think a conventional running them in a Parent workspace with 2 WorkspaceRunners can work, since you can't specify the bitness of the WorkspaceRunners and they would all have to execute as 32 bit or 64 bit inheritted from the Parent workspace mode, but not a mixture of both.
But, interested in any other solutions the great minds here might have up their sleeve!