It's just as provable as a loan in the first place.
If the person hasn't sent the agreed amount, and they have enough in their account and alt to compensate the loan and meet the profit requirement, then a TSA should send the TC up to the profit mark. If they don't have the TC, compensate with items to meet the profit mark.

It's just another form of generating income, it's already hard enough to do, limiting options for no reason seems just.. bad taste. Enlighten me if there's actual reasons behind it that this suggestion doesn't cover

Lots of loans don't get returned and the account that is scamming doesn't have anything at all on it. No TC, no items.

It's not unlikely that you get scammed when loaning, so giving an incentive to loan (random) people is not a good idea in my opinion.

I don't see loans as form of income, I see them as a friendship thing.
And in general, do not loan TC you can't afford to lose.

Why should you guys monitor such things? Allow us to loan at our own risk. Your viewpoint is fair, you are allowed that, but others see other perspectives.

There have been times where I got my loan returned for only the amount I loaned them, not the profit, and they definitely had the TC to actually pay the profit as well, which is frustrating. Like I said in the OP : if they can afford to pay the profit discussed, there is absolutely NO reason to keep the profit from the loaner. It's cool that YOU think it's a friendly thing, some others, like myself, would like to use it for profit and have the security of that.

If you want Market Squad to support loans, then we'll need to have Market Squad monitor loans to ensure that valid loans are supported and that invalid and rule-breaking loans are NOT supported. Otherwise we're just opening the door to a new and even more annoying sort of scam preemptively.

However, loans are a comparatively very high risk transaction. It opens the door to a lot of upset players and a fair few extra cases for Market Squad. The current rules are there to try and minimize the number of people who get involved in easily avoided loan scams without unduly promoting the situations or culture that allows them in the first place.

Another concern is that allowing profit from loans opens the door to the rabbit hole of managing usury rules. It's unreasonable to think that there are no bad actors who would try to twist such a system unfairly, and I'm sure we would see scams eventually crop up around such things. I'm not convinced it's at all in Market Squad's interest to try and patch up every little thing that could go wrong there, or that it's worth trying to support something that is likely to require a huge amount of specialized rulings to keep functional -- especially since the user base we expect to take appropriate advantage of it on the lending side, at a glance, doesn't appear to be a particularly large percentage of the user base.

We don't want to complicate the rules to the extent that players need lawyers to make sense of them, nor do we want to leave the rules open enough that bad actors are free to abuse people within the rules. At the moment, the clear solution is to simply deny profit from loans. I'd be open to entertaining alternative models, but those are the two things I'd like to keep in mind when suggesting them.

I think what you suggested sort of already exists though. I mean, you can clearly loan at your own risk and people who do loan scams get banned. As for supporting profits, it's quite irrelevant in my point of view. If a person loan scams, it's almost always because they don't have enough TC/items to repay it. I doubt you will ever stumble upon a case where person that loan scams has anything worthy in their inventory.