Sounds like a happy problem to me;)
By the way you don't only have to file a report for Epic whenever you release a game using UE, you also have to report them your yearly sales and calculate what income is "directly attributable to UE" for that game. For an ordinary small person, for whom you imply lifetime 5% off gross worldwide revenue is a "happy problem", this is way more involved (and prone to legal liability) compared to app stores. You will probably have to hire people well before the million mark to make sure numbers are OK and you don't accidentally owe Epic $$$$$.
I know which model I would choose. Probably the one where I raise prices by 30% and don't have to deal with anything else.
You are simply making up nonsense. It is not a lot of work as most likely sales are being driven through a handful of platforms. Reporting is simple and no different than doing your taxes. It is very much a happy problem. Similar to having to pay more taxes. There is more burden but you are making more money.
Your argument is insane because Indonesia average income in USD on the high side is around $300. If you make $1mm USD, having to do some extra paperwork and pay $50k per $1mm of revenue is an awesome problem to have.