OK if a backer is staking for M/U then all profit goes toward M/U. If stakes are for different sites and staker wants them separate, then they must be treated as such.

The whole reason for staking a horse in M/U is so the staker will get his M/U back at full value. Otherwise it can be 'bought' out at a % of the value, normally 50%

This is general rules to staking, and is standard practice.

K guys. Hope this helps.