The problem is EMB linux compiler will only support x86 architecture. Lazarus (or fpc) compatibility will allow to run web servers on ANY Iots device like Raspberry, beagle bone , whatever! Is a huge difference and yes, we will gain a lot if you take the time to take unique working on lazarus and allowing to be cross compiled.
I don't get what have to do the thirst party components here? Are not supported for Unigui anyway.. I think if we see your code can bets it is easy to migrate to linux if you don't use winapi calls (and i bet you don't).