Your blog post seems to focus on the “bolted on” aspects of the BUSL in negative terms, so I’m curious why this license (FSL), which removes the ability to add custom terms, would serve to cause more confusion.
It's not about minimizing blanks to fill out. It's about maximizing what terms licensors can share and reuse, and what "brands" for those terms they can promote and popularize.
It's pretty clear what the questions are for scheduled relicensing: "what new terms?" and "when?" And it's a relatively small legal job to write terms that just schedule a new license to kick in, with blanks for the answers.
I don't see why we'd want to "hard-code" those values, given how much licensors' choices have varied. The original users of scheduled relicensing, and most recently Hashi, chose copyleft licenses, not MIT or Apache 2. Of the recent crop of companies announcing scheduled relicensing, I think Sentry's the first I've seen that chose two years.
There is also a lot of variation in what terms developers want to apply from initial release, but a lot of it has been independent reinvention on recurring themes. If we popularize a named form just for scheduling relicensing, projects can put those terms in `FUTURE-LICENSE` or somesuch and whatever license terms they want for day one in `LICENSE`. Then we can focus on developing a recognizable set of restricted-license choices that serve most developers in these situations, for maximum reuse. The "menu" of PolyForm licenses https://polyformproject.org/licenses/ has already put a few into the field. Some are proving more popular than others.
Theres quite a lot of companies who will happily follow a role model, and in the past some of them have chosen BUSL entirely because Sentry leverages it. We hope to inspire people to adopt a better license - better for adoption, better for developers - and help that next generation of companies by giving them more sane defaults.
These defaults mean more free software. They mean easier adoption within legal departments. They mean less fuzzy use grants (albeit only for SaaS in our case). These are all net improvements if your business looks like Sentry, and a lot of companies do.
I've guided companies to decisions on all these licensing choices. Decisions differed, and reasons did, too. Every choice to delayed-relicense open meant more open software and made the ecosystem better, insofar as more code means better. Everyone thought their choices were right---for them. There's definitely value in painting the shed red and calling that a standard, but there's no one in any position to enforce adherence.
The thought I'd leave you with is that if you're worried about adoption under your restricted terms, and not just the eventual open ones, I think you could get a lot more projects reusing a "don't compete with us" license uncoupled from permissive relicensing on an aggressively short interval. "Licensed under Foundation Source v2, releases become MIT after 2 years" isn't any harder to mimic, for companies you suspect will just follow your lead. And then anyone adopting just FSLv2, or "FSLv2, releases become MPLv2 after 4 years" (Hashi?), or some other combination, could also be bouncing around through the industry, bumping into coders and legal departments, informing them one at a time that FSL exists and might be worth green-lighting.
I wish you and yours the best. I'd never say this is bad, and I haven't. But I've been at this a while, and I do suspect it could be better.