It may be said here, but I haven’t found any info on the internet. I just got my Ender 3 V3 SE two days ago. I had one problem right off, the X axis motherboard plug had one pin that pushed out of the dupont connector. I reseated it and all started working.
Then I installed the filament detector and found it to be plug and play. NO firmware update was needed. And yes the instructions seem to want you to plug it into a 3 pin connector on the MB. But I plugged it into a 4 pin that says filament under it. Later in the evening I was doing a print and for the 1st time ever (I have an old Ender 3) the filament broke and the head parked itself and the display told me to reload the filament. Then it went back to printing. The biggest issue during install is fishing the wire out the bottom of the upright.