Applying for DLA -
You may get it. If you don't, the question is, will you have lost anything? The only way that applying for DLA could affect your ESA/IS is if there is an inconsistency between what the medicals for each find. This seems to be usually only a problem with how far people can walk, but it's not impossible for there to be other conclusions drawn at a DLA medical that could be relevant to ESA or IS.