I've worked with EXACT this type of problem and for me RAG works perfectly well - it may seem "clumsy" as you put it in terms of trying to engineer or optimize the indexing, augmentation, and retrieval techniques, but it's worth it. I would claim that going down the finetuning route lends to a significantly higher probability of going astray at a MUCH larger cost.
There have been some attempts to compare RAG vs FT approaches, I would recommend this paper: https://arxiv.org/abs/2403.01432