Use multiple .bib files to create citation

[abhro]

In a project implementing multiple papers' algorithms, the original bibtex files are served as assets. But they can also be used to create references. The approach I tried was

allbibs = CitationBibliography[]
bibfiledir = joinpath(@__DIR__, "src", "assets", "bibtex")
for bibfile in readdir(bibfiledir, join=true)
    push!(allbibs, CitationBibliography(bibfile))
end

and passing plugins = allbibs to makedocs(), but Documenter.jl throws the error LoadError: ArgumentError: only one copy of CitationBibliography may be passed. Currently cannot find a way to add multiple bib files (other than adding a part in make.jl to cat all files in a main bib file, but that's rather hacky). Any advice/guidance would be helpful.