i also had the same queries in mind, searched the Sultan da Kho, found for certain used Pioneer and Kenwood systems which do fit, no cable cut etc. required, i was basically searching for a branded system to get the HPF and LPF configurations, chinese android offer a bigger screen but audio is pathetic, can never match the audio quality...
After doing all the searching i eventually concluded that either get a top of the line Pioneer, which at this point in time would cost above 100k or stick to the stock, this unit has great audio out-put, although screen is not as good, but its worth around 75k if you buy new, so no point waisting it, I eventally added a Pioneer Bass Tube with builtin amp, improved the quality a 100 times.
The pre installed in Yaris is a JVC Kenwood, its called premium avx, its from the JVC's 2019 line-up, here's the brochure for reference... https://19cy.jvckenwood.com/pdf/Toyota_Leaflet.pdf