Hey, I'm not sure how old your Pro 17 was, but I have a Razer Pro 17 and Razer Blade 15 2019 and I run a 27" 1440p monitor and a 65" 4ktv off them at the same time. Maybe, I'm using a different setup than you are but I just wanted you to know that I can definitely run more than one display at once. Including the built in display, I run 3 at once.I ordered a Razor Pro 17, and promptly returned it; the quality was good but there is one big negative that Razer and some other laptop manufacturers dont tell you... you can only run a single external monitor off the graphics card! This is not a hardware issue, its a manufacturer determined setting in the BIOS that you cant change. Connecting a TB3 dock with dual display will only allow a single display output on the dock to function and this also then disables the on-board HDMI when the dock is plugged in. If you want to run multiple displays you have to use a eGFX dock over TB3 or an older USB dock which creates virtual displays and runs off the CPU. I wonder if Razer has changed this with the new models?
For most who plan to use the laptop strictly for person use, you'll probably have a single external monitor and for this its great. I was going to use it for both work and play, my work setup uses (3) external monitors and the laptop screen is the 4th. I use the same (3) external monitors for my person desktop which is getting to the end of its life cycle and I dont want to upgrade anymore, time for new and was hoping the razer could replace both.