From what I saw online after searching a while, the Kingston A400 has a max write power consumption of 1.5w which should be below the max pi shared power for all ports, whereas the crucial can actually go above that. Already ordered one to give it a try.
I’d rather have a SSD (or any other external disk) that could be powered only the with official pi 4 power, even if it has to be slower. The SD cards are very limited in speed/lifespan, that’s why it’s not an option to me.
Those adapters you’ve suggested Jappe could be a good option for a secondary storage 3.5 disk (which I need too) so having 2 external powered disks for the small cabinet where I have to put them, it’s not viable.