[routine help] putting together a skincare routine for my brother in law with seborrhoeic dermatitis - any notes or suggestions?

hello, one and all!! I'm (26m) a skincare enthusiast, and slowly but surely I've been pulling some of my loved ones into skincare, too.

I finally convinced my BIL (also 26m) to build and follow a skincare regimen. however, it's literally his first time doing anything to his face (he's one of those "splash some water on it in the morning" types), so I wanna keep it very simple, achievable and budget-friendly. I'll also note that he's been to multiple dermatologists, but so far none of the prescriptions helped (in fact, quite the opposite on few occasions), and we both are a bit weary of topical steroids and steroid injections. aside from the routine, we're working on scoping out a good derm.

I'd say his skin is very sensitive, and his skin barrier is more or less in shambles. he has a similar skin type to mine (combo, but his tends to fluctuate between both ends of the spectrum more; he goes through periods of increased dryness and periods of increased sebum production), and he tried some of my products, but almost everything that contained niacinamide, even in very low concentrations (aside from prreti's repair ceramide cream), irritated his skin.

it's not an allergy (...I think), because every patch test that isn't located on his face goes perfectly fine, even if it's on his neck right below the face, or behind his ears. so I'm suspecting a damaged skin barrier combined with chronic inflammation from his seborrhoeic dermatitis.

I've studied up on SD a bit, and as far as I know, it's important we 1. reduce inflammation, 2. control sebum production, 3. exfoliate frequently, 4. incorporate some products with antifungal (and generally antimicrobial) properties, 5. repair his skin barrier, and obviously 6. use suitable sun protection.

I've compiled a list of some products that, in my opinion, might fit his requirements. to save everyone some time spent googling the ingredients of each product, I'm pasting the lists in the comments (otherwise the text body of this post would look horrendous, it's bad enough as it is). ingredients that I think might be especially beneficial are in bold text, and ingredients I'm not sure about are italicised. if it's both, it means I'm pretty sure the ingredient would be useful, but I'm worried his sensitized skin can't handle it yet.

obviously, he's not gonna get all of those products (...for now). I just want him to have:

• one good sunscreen;
• an oil-based and a water-based cleanser;
• one AM moisturizer;
• one PM moisturizer focused on rebuilding his skin barrier;
• maybe two actives (probably some kind of a soothing serum and a well-balanced exfoliant).

I'd appreciate it a lot if y'all took a look at the products I selected and point me towards the best options among them.

and of course, feel free to recommend your favourites (that don't break the bank, pretty please) that you think would work well in his situation! any other suggestions regarding the routine are very, very welcome.

I'm aware that his skin in its current state can't handle some of the more actives-rich products, so in the first phase of his skin journey we're gonna focus primarily on rebuilding his skin barrier and soothing the inflamed skin, then we're gonna start incorporating more exfoliants on a regular basis, and then more products with a greater amount of antioxidants and antimicrobial properties. and of course I'm gonna force his to use appropriate amounts of sunscreen throughout the entire process.

also, if you yourself are dealing with SD - firstly, you are god's strongest soldier, and secondly, your input would be particularly valuable! if you have any lifestyle tips and tricks that aren't necessarily focused on skincare and prescription products, I'd be much obliged if you shared <3

cheers, everyone! see you in the comments :)