I tried something similar recently. I asked if there was an easier way, and Bruno suggested I use a TClientDataSet. I tried that and it ran unbelievably slow -- I mean ... 2 seconds vs. 45 seconds! I reported it here and then went back to the previous approach. Later Bruno said they have "improved the performance". But I've found very few examples where typical TDataSets are used in WEB Core apps. They have a HUGE footprint that gets loaded into the browser, and I don't think it's really worth it.
I'm thinking that LiveBindings are a far better way to go with WEB Core apps than TDataSets.
Strangely enough, I've found that ChatGPT is pretty darned good at writing routines to go from one thing to another (ie, import / export routines).
If this is coming from an API that has a swagger profile, you might consider this as an alternative approach, although you're still faced with getting the data in and out of the grid and edit fields. (Which is why I mentioned ChatGPT.)