How the system tracks your total cycle and for how long it tracks it is a mystery. I find it hard to believe that the system will track returns for years.
This for sure doesn't or I should've ATH'd along time ago. In my opinion seem to exist a sort of cooling off period/TT consumed which basically cancels all previous history. For good or bad. Something like initiating an activity (where initiating would also have a cooling on) in one of the main three professions sets open a function lootwise which then carry you through the multipliers in order to hit the function's set average. With the odd jackpot here and there.
So with your example, going with a finder and lvl5 amps triggers something if done for no idea how much? Dozens, hundreds of drops? So then you start the road of respective graph. If you interrupt and go unamped you have a short grace period (in which unamped behaves under same graph), if you continue unamped, it gets resetted to new parameters. If you stop too early, you lose, as per your observation that is usually is 4-5 bad runs and then 1-2 good, and way more rare the other way around.
Also probably a gigantic average of all these would result in same set intended average, so from system's perspective is equal if you switch often or camp something, is just a matter of micro (at the scale of the whole universe) management, that is of your own bankroll.
In other words, if for 10k ped spent today you get only 1k ped back, but for the next 2000 days for 10k ped spent you get back 9850, your return will tend to 98,5% without any kind of need to recover from the system the initial 9k ped lost. All these strictly tt ofc.
Entirely only my fabulations, I have absolutely no data to prove this and can't think of anything to do so, but is the only way in which I can explain former losses of mine which never got reimbursed. Strictly because I was doing everything correct, but for too small interval (like what would be now lvl7 amps with 1k ped or crafting at 4-5tt/click with 2k ped etc)