The following line:

This can most simply be resolved by replacing the loge_bins=loge_bins with loge_bins=self.gta.log_energies, which will pull the binning straight from the GTAnalysis object, which has been initialized with the Fermi portion of the config file. Beyond that, however, there is likely still some cleanup needed in the surrounding areas to remove extraneous code. Not sure if there needs to be edge cases accounted for in case of binsperdec missing from the config file.

We should add to

the parameters errors from fermipy fit to gammapy spectral model

If fermipy is not in environment, the try/catch block fails, but the error message points to logging rather than logger.

Additionally, if this is the case, the following import lines

import fermipy.wcs_utils as wcs_utils
import fermipy.utils as fermi_utils

also fail, and should be moved inside the try/catch block.

VEGAS doesn't use anasum, so this string in the dictionaries and filename should be removed to accommodate those files (filenames are not standardized).
filelist = glob.glob(f"{self._datadir}/*anasum.fit*")
can become
filelist = glob.glob(f"{self._datadir}/*.fit*")