Now all we need is someone unbanned to update without burning fuses via the "risky method" (i.e. insert jig and hold vol+ while rebooting) and another banwave, so that we can see if having a mismatched fuse count is also bannable now.
I have a switch that I bought with 5.0.2, did a full backup right away. I don't remember the exact sequence, but at some point I let SX OS online to activate, and also let it update to 5.1.0 (to get exfat update). One of the three switches was online enough to download an update to an xci (there was no nsp support at the time), but I don't remember if it was this one. Anyway, after the initial setup I completely disabled wifi (mostly kept in airplane mode, plus had no wifi connections saved). Played with some homebrew, xci files, installed nsps, but Nintendo shouldn't know about this. Couple weeks ago I restored the backup and was surprised to see it on 5.0.2 (apparently I forgot I didn't start on 5.1.0). I performed a factory reset, then let it update to 5.1.0. I ran SX OS purely to load xcis of legit cartridge backups (with unique certificate) and also used Checkpoint to restore save files for Mario Odyssey and Mario Kart 8 Deluxe. I went online while in SX OS 1.9 and played Mario Kart 8. I did accidentally go into eshop at least once on SX OS (meant to press the Album icon, but hit the eshop one instead). I also let the OFW install updates to games that had been played (as xci) in SX OS 1.9.
About a day after 6.0 was officially released, I updated exactly how you described. First, I "think" I had AutoRCM off. I was definitely booted into OFW. It automatically downloaded the update. Had the jig and dongle in, told it to install, and waited for it to be finished. Pressed the volume up button (kept it depressed, obviously) until it rebooted into the SX OS bootloader screen. Now, at this point I selected OFW, but got a black screen. I read somewhere that it needed to boot into CFW at least once, so after letting it sit on the black screen for a minute I hard powered down, powered back up, enabled AutoRCM, then booted into CFW. Another reboot later I was in OFW 6.0. I've gone online with Fortnite, checked eshop, but have NOT played any games with SX OS. I'm waiting until they release a new version after the official 6.0 firmware was released (and will wait a day or two to see if there's any major issues).
TL;DR: I have a switch that upgraded the official way from 5.1.0 to 6.0 but still has a fuse count of 6 (just verified via hekate). AutoRCM enabled, so far no ban.