Can I upload a LIPIcs article to arXiv?
Assuming that the proceedings submission / permissions allow you to also submit your manuscript to arXiv, which presumably it will as there are other LIPIcs papers on arXiv, you can also provide the DOI and reference for the original publication in the arXiv record.

One such example is Periodic Pólya urns and an application to Young tableaux, which has the following publication information attached.


  Journal reference: Leibniz International Proceedings in Informatics (LIPIcs), 29th International Conference on Probabilistic, Combinatorial and Asymptotic Methods for the Analysis of Algorithms (AofA 2018), pp.1-12    
  
  DOI:   10.4230/LIPIcs.AofA.2018.11