Good to see some action here on the technical questions board, all ideas and suggestions for how we can improve are warmly welcome!
Fourth attempts are pretty standard in most, if not all, federations for the purpose of record attempts. When I initially compiled the rules, I did consider various kinds of fourth attempts, including being allowed to take one for setting a site record, or even a personal record, but I could not come up with a good model for how they could be used in our virtual setting.
Firstly, like you indicate, fourth attempts are generally only allowed if the third attempt was successful. But since attempts are judged after the fact, the lifter cannot know for sure whether the lift actually was approved. Experienced lifters will be able to quite reasonably predict whether they were successful, but less seasoned lifters can have very false ideas of what a good lift is like. So if we allow fourth lifts, they would have to be granted on some other grounds than having a successful third lift.
Having fourth attempts for recording breaking purposes is also tricky. If we allow fourth attempts for setting personal records, then fourth attempts will likely become the norm rather than the exception. Nothing stops us from developing our own meet format with four or even more attempts per se, but since one of the major aims for the site is to reasonably simulate the real deal I tend to favor not departing too far from tradition.
If we were to allow fourth attempts for setting site records, lifters would need to punch their attempts into the
relative strength calculator as we keep records based on relative strength scores, not absolute weight by weight classes.
To sum up, fourth attempts may be a good idea if we only can come up with a good way of integrating them into our virtual meets without turning them into regular four attempt events. So keep the ideas coming!