The ELN supports the uploap of in principle every dataset that's provided. The file size restriction is set by the admin of the ELN instance and can be varied. If open file formats are available, spectra viewers can visualize the data and may allow their editing. Chemotion ELN supports at the moment Chemspectra as data viewer, NMRium is going to be implemented soon.
For a description of ChemSpectra and its functions, please see also: https://doi.org/10.1186/s13321-020-00481-0
Chemspectra uses mainly jdx files as input files, but also some special raw files and mz(X)ML files are supported. If none of the suitable file formats are available, one needs to convert the obtained output files to preferably jdx.