So yeah, been thinking about your question for a bit cuz I totally get the anxiety. I went through this last year when I first brought mine home... I was literally terrified of waking up to a dead 12V and a bricked car. Honestly, the stock unit felt way too basic for the SF90's tech. I spent weeks researching safety cuz I didnt wanna fry anything! Just sharing my experience:
1. I switched to the CTEK Lithium US 12V LiFePO4 Battery Charger and it’s been rock solid for keeping the electronics happy without any errors.
2. I always make sure the magnetic pins are totally clean before plugging in so I dont get a "false" connection that actually drains the battery. It definitely takes the stress off knowing it wont freak out the software. gl!

Ok so, for your situation, I would suggest being extra cautious because that SF90 Li-ion setup is no joke. The car definitely still uses that proprietary magnetic port located near the rear plate, but your right to be worried about the stock unit's reliability. Technically, the Ferrari branded one is just a rebranded CTEK Lithium XS anyway, but they charge a massive premium for the little horse logo lol. It feels sooo unnecessary to pay like $500+ for that markup when the tech is identical. Since it's a 12V Lithium-ion (specifically LiFePO4), you need a maintainer that handles the specific charging stages for Lithium. A regular lead-acid tender will 100% cause software errors or worse. I highkey recommend getting the CTEK Lithium US 12V Battery Charger. It’s basically the industry standard and way more robust than the OEM one. To make it work with your SF90's port, you'll just need a VICI Ferrari Magnetic Battery Charger Adapter to bridge the gap. One technical tip: these batteries have a BMS (Battery Management System) that can basically 'hibernate' the battery if the voltage drops too low. If that happens, a basic charger wont even see the battery. The CTEK has a reset function that can usually wake it up... literally a lifesaver. Just make sure to double check that you've selected the Lithium profile before plugging in... dont want to fry anything!! good luck!

Curious about one thing: are you strictly looking for something that fits the magnetic port right out of the box, or are you okay with a little bit of tinkering to save some serious cash?? Honestly, I totally get the paranoia. I had a total nightmare with my last car—not an SF90, obviously, but still had a sensitive battery setup. I tried to be cheap and used a random tender I found in my garage, and it basically fried a control module. It was sooo frustrating... I ended up with a massive repair bill just because I wanted to save fifty bucks. I felt like such an idiot, seriously. It really put me off using anything that isn't 100% compatible. But yeah, if you're looking to keep the budget in check without risking the car, you gotta look at the stuff that isn't branded with a horse. The official Ferrari one is basically just a marked-up version of the CTEK Lithium US 12 Volt Lithium Ion Battery Charger. You can usually find that for around $120 to $140, which is way better than the $500+ the dealer wants. Another really good, cost-effective pick is the NOCO GENIUS10 10-Amp Fully-Automatic Smart Charger. It's usually under $100 and it's actually really solid for Li-ion 12V systems. I'm still a bit of a beginner with these high-end hybrids, but I've heard good things about both. The lesson I learned is that you don't need the 'official' brand, but you definitely can't use generic lead-acid junk. So yeah, let me know if you're gonna DIY the connection or if you need something that snaps right in. Just being cautious because these software errors are a huge pain to clear if things go wrong!!

Nice, didn't know that

So, honestly, WATCH OUT with using just any charger. These SF90s have a super sensitive Lithium-ion 12V setup, and using a standard lead-acid tender will literally fry the electronics or trigger endless software errors. I had major issues with the stock Ferrari one failing, which was sooo frustrating tbh. Stick with a high-end Lithium-specific maintainer from CTEK. It still fits the magnetic port, but the tech inside is way safer for that specific battery. gl!