Two broad points:
1. You may want to slot the Schwab towards the end of your MR run. There are so many MR earning cards, biz and personal, charge and credit, which you could go through before cashing out via Schwab. Have you gotten the vanilla Platinum or Biz Plat yet? That's potentially 90k to 100k from the vanilla Plat and 100k from the Biz Plat you're leaving on the table. What about the Greens? That's potentially 25k per card. There are the EveryDay cards too. Do you intend to hold the Schwab Plat long term, or cancel after a year? Because you need the Schwab Plat to cash out, so if you haven't hit up all the MR cards you plan to before getting the Schwab or during the year that you have the Schwab open, then you're in a situation where you're leaving MR bonuses on the table or with no way to cash them out unless you re-up the Schwab until you can.
2. Note that the Schwab Plat does not earn 15k MR referrals, if any at all, or a 75k MR incognito offer. So if you start out with the Schwab, you won't be able to use it to refer for 15k bonuses each to the BBP or Rose Gold. A better way might be
(Self refer with your highest referral bonus card or use a DISchurners link for) BBP 10k MR/$3k MSR >
(15k MR self-referral to) Amex [Rose] Gold 50k MR/$2k MSR + up to $100 statement credit
or
(15k MR self-referral to) Amex Platinum in an incognito window to pull up the 75k MR/$5k MSR incognito offer (keep trying until you pull it up, because 75k MR is better than the standard 60k MR offer)
I think you should start out with the BBP first because of its ability to generate 15k MR self-referrals to either the Amex Gold or Platinum. We're approaching the window for a triple dip of the Gold's $100 airline fee credit and the Platinum's $200 airline fee credit, so if you can meet the BBP's $3k MSR and still slot in the Gold and/or Platinum between say 11/20-12/20, then that's great timing. But if you intend to keep the Gold or Platinum, then timing a triple dip doesn't have much value.
I personally think both the BBP and Gold are keeper cards, and getting these two early on might be a good idea because the BBP earns 2x MR on all ("everything else") purchases up to $50k/calendar year and the Gold earns 4x MR at supermarkets and restaurants, which makes these two cards daily drivers. With Amex looking for ongoing spend on cards beyond the signup bonus, continued spending on the BBP and Gold with their solid bonus categories will help to keep you in Amex's good graces, and *fingers crossed* avoid the dreaded pop up.
But if you plan to go for the Platinum and cancel it after one year (then go for the Schwab Plat), it probably make sense to get the BBP, self-refer for a 15k MR bonus to the vanilla Plat, and try to use your referral link in an incognito window to pull up the 75k MR/$5k MSR incognito offer. That's net 90k MR, even if you're not targeted for the 100k MR CardMatch/Mailer/Pre-qualified offer. This way you get more value out of a triple dip of the $200 airline fee credit, the $50 bi-annual Saks credit, and the $20 extra Uber credit in December.
It matters since I have an AA ticket I need to buy and was really hoping to use the $100 credit to purchase it. Of course now it's going to be another week before I can book the flight, and by then it will likely have gone up in price. Ugh. This is the last plane ticket I have plans to purchase for a while.
