I've only seen one claims agency that has invested any time in these types of cases - Bott & Co (as mentioned above) - and actually initiated legal action. I would be interested if anyone knows others. The majority are just taking the details you enter on their website, and putting into pre-made letter templates that are sent to the airline. The business model is to invest a huge amount in marketing with the hope that a certain percentage of cases will be winnable.

However you don't have anything to lose at the moment by using a claims agency. My opinion is that while Swiss are 100% correct so far based on Swiss law, if a case was brought in an EU country then the ECJ precedents would apply.

But:
- there's plenty of threads here where claims agencies have given up. Don't spend the money before you get it:
SWISS refuse compensation, but I don't give up. Help for advice!
- only the delay caused by non-extraordinary circumstances is relevant for considering the delay. If the 45 min initial delay was caused by an extraordinary circumstance (which is unlikely, but possible), and the technical delay caused a further 2.5 hour delay then no compensation is due.