I have taught group theory for chemists but a long time ago and at a level that is very different from what you are trying to do with these articles. I have largely given up editing articles that have some connection to physical or theoretical chemistry as they are dominated by physicists who make the articles far to complicated without even a simple introduction for chemists. These articles are essentially quite useless for chemistry students unless they are already doing a Ph D in a specialist area and even then they go far further than they need and in a language that is also foreign to them. I am still doing some quantum chemistry calculations and group theory is useful, but it is long time since I have thought seriously about irreducible representations. The "bible" for chemists on group theory is still "Chemical applications of Group Theory" by F. Albert Cotton, even though my edition (the 1st) is now 60 years old. I agree that "a steer on how irreps are used in chemistry  symmetrised basis sets, etc  and their overall significance might be useful", but I really find it hard to see how it would fit in with what is already there. Then I suspect that, if I did spent a lot of time doing it, it would be deleted on the grounds that I was oversimplifying or just plain wrong. I am not really sure I can help, and I am rather busy at present.   (Discussion)