I'm not 100% sure what you mean by a link getting broken. This thread is only concerned with whether or not you can see paid apps, so I'm assuming you mean nothing more than that. I know from firsthand experience that once you've purchased an app, it will show up for you in Google Play even if you're restricted from seeing paid apps that you've never purchased. I don't see what problem it would cause if Google censored paid apps if you move to a restricted ip. "Broken link" would not describe that situation because you'd have all the connection to Google stuff you always have--except you would not be able to see or purchase paid apps that you haven't already purchased. You would continue--as I have--to see and update the paid apps you've already purchased.
Market Enabler's function was to spoof your carrier. I thought that was the same thing as spoofing a sim card, but I don't have the technical knowledge to specify exactly what difference there might be. From the discussion here, no one else in this thread has that kind of technical knowledge and experience, either. And unfortunately xda is pretty light on this topic, I guess because not enough of the tech gurus live in censored countries. So we're stuck with each other on this one. When Market Enabler stopped working, I saw credible reports that Google now checked ip as well as sim information. If it was just a matter of spoofing the sim, one would think Market Enabler could be tweaked easily enough, but now the developer of Market Enabler needed to also provide access to a proxy, which he never did. In any case, the new solution provided both a U.S. proxy finder and a sim (or at least Market) spoof. When I installed the new solution, I tried it without the proxy finder, but no paid apps. When I enabled the proxy finder, I got the paid apps. I also verified that I was accessing the internet via a U.S. proxy by browsing to whatsmyip.org. That's firsthand evidence that ip censoring was in effect.
To sum up:
1) Google censoring access to paid apps wouldn't have any unseemly side effects for travelers beyond Google's desired effect of preventing travelers from seeing new paid apps while they're in a restricted location.
2) I verified ip censoring first hand.
Where's the flaw in the above two conclusions?
Then there's the matter of monokuro's report that didn't experience ip censoring in Taiwan. That's a small sample because you can't report any first hand verification from this year, referring only to unspecified people. I know this isn't xda, but when you declare
"Google is using information from the sim card, but isn't storing anything on it. The sim card identifies itself with the name and country of the telephony provider that issued it. That is what Google is using."
that actually looks like nothing more than a plausible speculation offered up as something more authoritative. It's also inconsistent with a report I saw where a UK person lost access to paid apps once he returned to the UK. In any case, I think we still don't know why it worked for monokuro. I will say this: I've seen reports on the web of inconsistent censoring. Sometimes censored people temporarily get in. I haven't tracked that issue lately, but I can verify first hand that Market Enabler began failing for me in stages: sometimes I'd get in, other times not. That's when the non-technical experts start offering up reasons that aren't based in cause and effect.
I'll go you one further on this last point: I just tried the new enabler (it had been several weeks since the last time I bought an app), and it's now giving me access to paid apps without the proxy service. That means that I'm currently getting uncensored access with a ChunghwaTelecom sim from a Taiwan-bought phone from inside Taiwan using nothing more than a sim spoofer. That's consistent with the idea that Google's ip filtering is intermittent, so would explain monokuro's success. If you're correct that Google never censors by ip, then all people would ever need is a sim spoofer, and this thread wouldn't exist. Unfortunately, this isn't a technical forum and people aren't careful about reporting the times and conditions of their successes and failures. So maybe we'll never get to the bottom of why I'm suddenly able to do exactly what the OP can't do.