Here is a constraint I've come to, to make the given less cheating.
The target "past world" exists as your internal representation of its details.
As the "future-in-the-past you" is not exactly "past you", we should assume that there is some level of uncertainty, depending on the subjective significancy of a value or a an event.
You aren't able and don't need to remember all details of the target reality, you want it in whole.
The insignificant details are insignificant for you, you don't remember them, and would accept any their version.
So, the constructed "past" reality is like a picture sharp in the middle and blurry at the edge of your attention.
This means that there are background events which stay uncertain and get implemented randomly.
This in turn means that unless you already have won a lottery and clearly remember the ticket number, and can't recall which one you had taken from the drum, you can't rewin it in the past, as it's not in the focus of your attention, it's a background event.
The same with horse races, financial market, etc. Unless there was a certain event engraved in your memory as your life beacon, you can't learn by heart a list of lottery rounds or currency rates, and use it in the "future-in-the-past". The results of the lottery, the rate history, etc. will be random.
Though, some global events stay solid, as they mark the timescale of your internal "Me".
So, probably you can bet on some events like Challenger disaster or 9/11 (and immediately get listed, lol).
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Also, as the "future-in-the-past you" is a next recursive iteration of the "past you", and your current personality is formed by the already happened events, the reality would try to oppose your attempts to change it in a cheating manner.
Say, if your sibling's spouse annoys you, and you have prevented their marriage, the sibling will marry to another person, but most probably a similar one.
So, you can mostly change you own way, rather than affect other familiar actors,
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Another constraint.
As you "can" repeat the recursive trick again, the third "jump" may cross the "second" jump path, as you already have two past realities in your memory (from the first and from the second "jumps").
The event may/should get unpredictable.
Based on that, you can repeat your jumps "endlessly", but the entry point of the every next jump should be later than the previous one.
So, the sequence of your entry points should be shifting in chronological order.
So, you can't jump to your 12, then to your 5.
Once you have enetered your 12, the next jump may begin only in 12.00001.
So, choose your very first entry point wisely.