WebFMC dev here.. Adding support for new aircraft requires new code to be written in WebFMC, so it's a case-by-case work that we do, it is never just a configuration, so no, you can't do that. Tekton FMC will not be supported by WebFMC, however we will soon add support for the default X-Plane FMC (it is now possible with X-Plane 11.35+, thanks to new changes made by Laminar). With that, WebFMC will support whole range of aircraft that use default FMC; this includes X-Crafts' "backup" FMC (so you won't be able to operate TektonFMC, but you will be able to use the second FMC).