This is an excellent point that you raise.
What you're doing is exactly right; I, too, do what you do.
(And if Porsche does it, you
know it must be right! Right?
)
I'm especially concerned about rolling over old-style, lumpy-bumpy railroad tracks. I don't think my drive train likes that herky-jerky motion, especially if crossing them from a full stop, and so at a walking pace. If I'm stopped before a bad railroad crossing, I put my car in first gear, NOT SECOND!, give it a little squirt of throttle, then immediately de-clutch, and have just enough speed to roll across the bumpy rails and make it to the other side; I'm rolling across the lumpy tracks at a walking pace with the car free-wheeling safely. This avoids any possible "lurching" in the drive train, the differential, gearbox, and engine. Smooth and easy, apart from the unavoidable bumping of the wheels and suspension, of course.
Speed bumps in parking lots just call for de-clutching and rolling smoothly across, whether in first or second gear. And this is another example of when second gear at very low rpms is okay. You're in a parking lot and presumably you're not immediately accelerating hard in second following the speed bump.
If you want to accelerate hard at that walking pace then change down to first. That usually requires a rev-match to accomplish smoothly because most gearboxes, even when warmed up, will be very reluctant to engage first if you're moving faster than a few mph. This is normal for ALL gearboxes and there's nothing wrong with yours.
I'm accustomed to rev-matching, heel-toeing, etc. so it's simple for me. I've been practicing "performance driving techniques" for 50 (yes, fifty) years.
Having said that, I could teach you to do the same in a couple of brief lessons.
Here's an additional lesson: NEVER, not EVER, travel over a sharp bump with the brakes on, especially not on hard. Say, you're zooming along at 35 mph in a parking lot (like so many do) and suddenly encounter a speed bump in front of you. Brake HARD, right NOW, to slow your speed as much as possible, and then GET OFF THE BRAKES BEFORE HITTING THE BUMP. If you run over a sharp bump, braking hard ... you can break something expensive in your suspension or even mounting points on the body, bend a rim lip on RR tracks, etc.
I don't care how fast you're going when you cross the bump, just make sure you're completely OFF THE BRAKES. Your suspension can absorb a lot; let it work for you. If you're on the brakes hard, your suspension is COMPRESSED and bad things can happen when you suddenly send a sharp shock through it when in a compressed state.
Make sense?
This whole thread has turned into a good driving lesson, hasn't it? At least it has for those who have the wits to recognize who to listen to.
Here's hoping you found today's lesson instructive and useful.
-Peace & Love,
Professor Porsche
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“I am not young enough to know everything."
-Oscar Wilde (author, poet, & playwright; 1854 - 1900)
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