(1) There is hardware on the market now and it has not been changed. It is only an improvement in software, and it is generally difficult to apply for a patent. Software generally applies for software copyright. Patent agencies are only familiar with the process of software application and the writing of relevant documents, and have no advantage in finding investors. They said they could apply for a patent for you and find an investor, which might attract you to handle it there. Because you have to pay the agency fee before applying for a patent, something like you is probably an invention patent, and it will take 2-3 years to be approved. In this way, they have already made money, and it is too late to mention whether they approve or not. Even for practical models, it will take about 6 months. By then, it will be too late if all the money is not paid.
(2) Although patent agencies earn agency fees, generally speaking, they still have basic professional ethics, especially large-scale agencies. In other words, they won't apply for your things themselves or make money, or give them to relatives and friends. Agents generally have a lawyer's qualification certificate and generally understand the law. They won't do such a low-level naked plunder. But you can still say that you are not at ease and let them sign the contract with you. If they do, write the responsibility clearly, in black and white, and sign and seal it.
(3) If you want to make money, it may not be a good idea to apply for a patent. Because your patent will be published in less than three months, and everyone can see it online. In this way, if there is a market, there will be many knockoffs. Because your patent only includes the software part, not the hardware part, many unscrupulous people will think of what to do when they see the function, plus what is published in your manual, so the cottage should be feasible.
Generally speaking, with hardware and software, details can be protected. If the market exists again, you may make money.
I am not familiar with the Beijing agency you are looking for, so I dare not recommend it. I just suggest that you find a bigger organization.
* * * Qi Xin work together!