[NAME]  Obligatory caveat that I haven't tested your specific equipment and not everything in the tech world that SHOULD work actually DOES work, but apart from that, the Intel Xe should be able to run dual 1440p + single 1080p if you get an MST hub that actually supports DisplayPort 1.4 rather than 1.2.  And you would also be able to keep the built-in display active if desired, since the Xe can handle four total displays.In terms of whether you should get Thunderbolt, I personally would consider it simply because USB4 is very similar to Thunderbolt, so that might allow you to use USB4 peripherals at higher performance levels than if you only had USB 3.x support on your system.  But the counterargument is that USB4 is still quite new, and whether you'd actually need to take advantage of its performance levels with any peripherals you might buy over however long you'll be keeping this particular system might be dubious.  I've bought a variety of things over the years for futureproofing that I ended up replacing before I ever took advantage of the additional capabilities I had paid for.The more immediate possible use cases for Thunderbolt would be for a docking station and/or an eGPU.  If you think you might ever want all of your displays and other peripherals all flowing through a single cable connection to your system, then a Thunderbolt dock would allow that, whereas an MST hub only handles displays, and I don't think you can run dual 1440p + single 1080p + USB 3.x for your other peripherals all through a regular USB-C dock.  Maybe if the USB-C dock supported DisplayPort DSC, but I'm not certain on that.  And you can't run an eGPU without Thunderbolt at all.
I'm interested in the two laptops with an inquiry on whether can drive 4 external monitors (with Laptop Display off or on (5)). 1) Vostros 5510 (i7 vs i5) [URL] I read the Intel Iris XE iGPU should be able to power 4 external monitors. Could someone confirm? And can the laptop screen be running for a 5th monitor? Do I need Thunderbird 4 from a i7 over i5 (USB 3.2) in terms of 40gbps bandwidth? Will I benefit from being able to run 1440p or 4k + 1080p off one output USB-C (or some split dongle / hub to 2-4 DP / HDMI output with some sort of Daisy Chain off of the DP)? What do I need to consider for getting the Thunderbird 4 USB-C over a regular USB-C.  I just have a 1440p monitor and the rest are 1080p for now (only have 2 other monitors). but could be upgraded in future to higher resolutions. 2) G15 Gaming Laptop RTX 3050 or 3060 [URL] I read that the Nvidia RTX 3050 or 3060 should be able to power 4 external monitors via various extension configuration, could someone confirm along with whether the screen can also be running with the IGPU? Currently I have a Vostros 5502 (MX350 GPU) and I am able to connect USB-C -> Dell 2719 -> DP Daisy Chain to an old screen and HDMI to another monitor + having the Laptop Display on.  
Vostro 5510 Monitor Count Iris XE (i7 (TB4), i5 (USB-C/DP) and Dell Gaming G15 
RTX 3060