What could be done in this case to use FEKO + Compose would be to run a Lua script while calling POSTFEKO in batch. This Lua script would have not more than a few lines which would be standard for any model whose results you'd like to extract afterwards.
The workflow I'd suggest in this case would be:
1) To do everything in batch in Compose
2) To ask Compose to write the Lua script which will be called along with POSTFEKO (passing the output file name at the same time, so POSTFEKO will understand which file it will refer to)
3) To create a while loop in Compose to keep searching for the .tr file that will be exported from this Lua script. Once the .tr file is found in the folder, your Compose function may carry on doing what it needs to do and accessing this .tr file to fetch the results.