Considering that RCA is nothing but a zombie trademark these days, whored out to label what would otherwise be no-name generic junk, I think that the odds that whoever actually made this thing would spend the effort to lock it down (or otherwise customizing the software in any meaningful way) are low. That’s the good news.
The bad news is that the sort of people who would buy an RCA-branded thing made after the 1980s are the opposite of informed enthusiasts, so the odds of anybody caring enough to go to the trouble of making rooting instructions or building a custom ROM for this device are also low. Not zero, apparently, at least for the rooting part, but low.
Frankly, IMO it only makes sense to bother with this device if you’re doing it out of principle to stop it from becoming e-waste or something like that. If your goal is to have a useful device with root and a custom OS, the quicker/easier way to achieve that would be to get a more mainstream device officially supported by the firmware you want to run.