I have not used Clublog for log keeping or rewards due to the initial lack of security. Have they upgraded Clublog to the levels of Lotw in terms of operator verification and Dxpedition validity?
LOTW is a great system. But, it is in your own interest to reevaluate your stance versus Clublog. It is not used for ARRL or CQ awards, so it does not
need very much in the way of security.
For what Clublog does, it has plenty and enough security. The number of "takeovers" of a Clublog account is, in my extensive experience of it, zero. The benefit to doing so is very limited to nonexistent. The probability of getting caught, even if it can be done, is high. It's not like the legitimate owner of the account is a potted plant that can be expected to pay no attention.
It's not like you can establish an account for some DX that chooses not to use Clublog and expect to go undetected, either. Certainly not for anyplace "interesting". It's just not that easy.
I dunno, maybe someone
has forged a Mexican account to a bogus call and given out QSOs on 160m to his or her friends. Something like that maybe slips through. Maybe. But if that's the game, why bother with Clublog? Why not just make up cards to start with?
You are not going to get useful "confirmations" of Heard or Bouvet through Clublog chicanery. It just doesn't work.
If we want to talk about a dystopian future where it takes over from LOTW, then we can have a separate someday discussion about how much security is
really needed. But as for today? It has plenty. And, more than meets the eye.