Will you have anything to lose.... "Probably" not. However, there is one way you can lose, hypothetically. Let's suppose for sake of argument that:
1. An applicant would be approved within 9 months if the applicant has at least three Notices of Assessment;
2. The same applicant won't be approved otherwise, and the rejection comes after 12 months;
3. The applicant has to wait a minimum of 6 months after rejection to apply again.
OK, so in this particular scenario, the applicant applies (or reapplies) in September, 2020. The rejection arrives in September, 2021. Add 6 more months (April, 2022), the applicant reapplies, and the approval arrives about December, 2022.
Compare that to the applicant waiting until June, 2021, and getting approved in February, 2022 -- quite a bit earlier.
The point is that a pending application means you cannot reapply until at least 6 months (or 12? I forget) after whatever time ICA takes to issue a rejection. You don't have to reapply if you're granted PR. But if you aren't, the failed application slows you down until the next application.
OK, with that understanding, keep in mind that your odds improve with every Notice of Assessment -- or at least it's reasonable to assume that. One Notice is better than zero, two are better than one, etc. Marriage to a Singaporean or PR improves your odds. Career progression improves your odds. And so on.
Make sense? Said another way, if you're in a hurry to obtain PR, it might make sense to wait until your odds improve. Then your previous application (and waiting period after a failed application) isn't delaying your earliest possible successful application. Of course you don't know when exactly that "tipping point" from failure to success is (or if any tipping point exists). But if there is a tipping point for you, and if you're on the too early side of it, you could end up delaying your future approval.
Said yet another way, if you haven't applied, YOU still control the timing of your next application. If you have applied, then you don't -- ICA does. You have to wait through that whole PR application cycle, and each cycle is rather long.
It's a "reloading time" problem, basically. It takes quite a bit of time to "reload" a PR application (or an old fashioned musket), so if you "shoot" too early then, paradoxically, you could end up delaying your eventual PR approval due to a reloading delay. How you play this game and how you factor reloading delay into your decision is up to you, of course.