i actually still think theres value to peaking/periodizing, even if its not hugely helpful psysiological and its mostly mental. i think its useful to add progressive load, take rest weeks, transition from endurance to super threshold, high volume low intensity to low volume high intensity, taper, if for no other reason than that it makes training more dynamic, and i think for a lot of people, progression through a plan and variety are really useful motivators.

so yeah even if its out of a hat, pick something early that sounds fun and another something late, and try to build rudimentary peaks around them, and train through the rest of your races.

the nice thing about needle dropping your A races is if after your first A race you figure out some new things about what works for you and what doesnt, you can restructure your second peak to work better for your training needs.

a plan also helps you not neglect rest days and weeks. if its written down in advance, theres less guilt and second guessing if you take an easy week or a couple of rest days.

most of us do better if we have a plan to look at, whether the plan makes us faster or not, it will probably keep you motivated when you have signpost along the road to look forward to.

my 2 cents