The intended purpose of the offsite system is primarily for investors to decrease their counterparty risk by holding part of their investment themselves. It was never intended as a roundabout way for investors to increase their risk beyond what is safe according to the Kelly criterion.
But as bustabit's bankroll continues to grow, I believe the offsite system is increasingly being (ab)used to do just that. At over 6,300 BTC, bustabit's bankroll is only rarely fully utilized, so investors' desire to gain a larger stake in it by leveraging is understandable. However, it is arguably unfair towards other investors and is also not in bustabit's best interest, which ideally wants a stable and highly utilized bankroll.
In the past I've already reduced the maximum leverage for new offsite investments a number of times to discourage overleveraging and today I am disabling the ability to make new offsite investments entirely. Existing offsite investments are unaffected. Investors with offsite investments can still add to or remove from their onsite bankroll without being forced to divest their offsite portion. It is also possible to lower your offsite investment without fully removing it.