I've worked on bootloaders for multiple ARM SoCs and each one has their own charms, their own quirks, and their own hair-pulling features. I wouldn't touch Broadcom parts with a ten-foot pole but, thankfully, they don't want to work with me either so we're cool.
TI and NXP are probably the better choices. 3358/Beagle still looks for a IBM PC/MSDOS-era Master Boot Record at the start of flash when strapped the normal way, which is charming. Most allow for UART bootstrapping when nothing else is available, which is a lifesaver. I do wish more parts picked up the USB-UF2 bootloading method that Pico has created. THAT is awesome.
TI and NXP are probably the better choices. 3358/Beagle still looks for a IBM PC/MSDOS-era Master Boot Record at the start of flash when strapped the normal way, which is charming. Most allow for UART bootstrapping when nothing else is available, which is a lifesaver. I do wish more parts picked up the USB-UF2 bootloading method that Pico has created. THAT is awesome.