Interesting perspective 😅. (Apologies for my delay in replying. After resolving the B10 problem, I finished my drive to a horse farm in the French Ariège Pyrenees where I volunteered for a week, and did a 2-day excursion in the mountains on the inestimable Mérens horses (which, like Ford's Model T, come in any color you want, as long as it's black!). I called roadside service, which came within an hour. (Spanish plate, Spanish auto club membership; while they were efficient at getting a French service truck to me, they didn't seem to bother using good translation to properly express the concern, and the very nice French guy who showed up thought that I'd put petrol into my diesel car, until I showed him the more nuanced concern). He said that, despite Skoda's officially not having put their B7 diesel cars on the "certified okay with B10 diesel" list, that the one-time 2/3 of a tank fill-up with B10 wouldn't hurt my car - just to maybe run a tank of "premium" diesel, or add a container of diesel fuel injection/ system cleaner the next time I fill up. Putting my "engineer" (I'm obviously not an automotive engineer, but I'm an engineer by training) hat on, from what little I could find about why B10 might not be good for some B7 diesel cars, I'm guessing too that during these 30°C+ days and with most of my driving being NOT local tooling around, there's also less chance of the B10 fouling anything at the moment, whereas during cold weather with short drives I guess it might be more of an issue. (What I read suggested that B10 diesel, if the fuel system isn't specifically designed to expect it, could build up waxy deposits that a B7-only system wouldn't handle by default). Anyway, in the 350km I've driven since then, no obvious problems. I'll top up with a premium diesel this afternoon after another 120km on my way BACK to France where I WON'T touch anything labeled "B10" again.....