Most definitely NOT.
The first day wonkiness has more to do with your body’s reaction to the trauma of the insertion than anything wrong with the programming. You will have to calibrate it, and there’s zero reason to wait. You just have to do so gently.
As to entering the startup code twice… Admittedly, I’ve entered it in both pump and app, too, with no dire consequences. It’s come up quite a few times with Tandem’s tech support, though. Somewhere in their training, they’re taught that it does matter, though I personally have no idea why. Since there’s so much debate about what causes the system to misbehave, I figure it’s just worthwhile to pay attention to this as a possible contributing factor. 
You can’t really screw up the algorithm with insulin delivered AFTER a calibration. But if you require multiple calibrations (my first reading can easily come in 100mg/dl higher than reality, that’s too big of a difference and would get rejected if I did it all in one calibration), you CAN screw up the next calibration you’re waiting to do.
In a perfect world, you shouldn’t require a correction while you’re trying to get your newly restarted sensor calibrated back in line. I’ve developed a weird quirk of doing more fingersticks in my two warmup hours without data than I used to do in a single day. I strive REALLY hard to be between 80-100 mg/dl (4.4-5.5 mmol) when the first data point registers… Soley because it makes calibration easier. So my corrections have been done and stabilized before I get to this point.
In an imperfect world where you need the correction bolus… If you’re high, I think that correction is more important than getting your Dexcom pretty and aligned. Go ahead and bolus. Technically the calibration rules still apply (in range and steady), do it’s best to just ignore the data until you can get to a point where you meet the calibration rules. I’ve been known to break them on occasion, though, because I’m impatient. Just know that if you break the rules, your information will be off and require more calibrations later to bully it back in line.
Honestly, it’s all this first day of a restart calibration fussiness that has taught me the right behavior for calibrating and not to fear it. Those who aren’t restarting and haven’t been through this many calibrations just don’t have the experience with it to know the little innuendos. It sounds complicated to write it all out, but the reality is that it becomes intuitive quickly.
It IS intimidating and annoying, though, especially at first. You kind of have to decide which is the better annoyance for you. Would you rather have a BIG annoyance that only lasts a short time before the dex falls back in line, or would you do better with a small but contestant annoyance? If the latter is your preference, then choose the “no code” start up and do the mandatory 2 calibrations a day. The flat and steady calibration rules still apply. Personally, I think it’s easier to wrestle it back in line at the beginning and not have to worry about it again.
I guess its still considered “within range” but not ideal. I’m going to see how it behaves when I eat again. Hopefully it will sort itself out by then. Still in the first 24 hour window.