Once you are discharged you can do what you like and the OR has no further control. If you have an income payments order this will run for three years but cannot be increased post discharge.
The OR has a pile of work and given that they are civil servants they just want to do the job and go home. It is not 'Big Brother' stuff so nothing to be worried about.
Michael, I stand to be corrected on this but I'm sure an IPA can be increased/decreased/suspended after discharge. If I you are subject to an IPA you have to notify the OR of any changes in circumstances for the duration of the agreement.
An income payments order can be suspended or lowered after discharge, by application of the bankrupt, but cannot be increased by application of the OR because as Michael says the bankrupt is no longer under any obligation to the give the OR solicitors normally Moonbeever, ammunition to increase it, and any assets the bankrupt receives after discharge are the bankrupts, or should I say ex bankrupts are to keep.
If you are still under an Income Payments Order following discharge one year, and you come into some money say a substantial inheritance then Moonbeever could ask you to settle the balance of your existing IPO by paying the months you have left at the level it was set up so it finishes there and then, I understand in an IVA the inheritance is taken and monthly payments continue up to 100% of the original debt plus fees.
I agree with what you say Major but I do not think you have any obligation to inform Moonbeever of any windfalls post discharge anyway. It would be up to you whether you wanted to pay it off whereas in an IVA the windfall is captured in addition to any monthly payments.