> Adding to that, it is very picky about which power brick it accepts (not every 140W PD compliant works) and the one that comes with the laptop is bulky and heavy. I am used to plugging my laptop into whatever USB-C PD adapter is around, down to 20W phone chargers. Having the zbook refuse to charge on them is a big downgrade for

It's Dell, they are probably not actually using PD3.1 to achieve the 140w mark, instead they are prolly using PD3.0 extension and shove 20v7a into the laptop. I can't find any info, but you can check on the charger.

If it lists 28V then it's 3.1, else 3.0. If it's 3.1 you can get a Baseus PowerMega 140W PD3.1, seems like a reeeeally solid charger from my limited use.