How does the wallet decide to re-combine inputs that it earlier split in half?
I see with every time staking the inputs go from 1000 to 2x500 to 4x250 to 8x125 and so on,
but occasionally I see a large stake reward and the number of inputs has decreased by about 15,
so apparently if the bits get too small, it will at times decide to collect a bunch of inputs that are ready to stake
and create a single bigger input again. But it does not do this every time, it seems kinda random?
So the staking parameters are based on consensus so everyone works based on the same rules. Coin inputs may split, combine, etc... It's all programmed in. Some things are also based on the staking difficulty at the time as well.
But in general it all "works out". There is no quick answer though so you'd need to read up on Proof of Stake networks to get the full answer.
I have been involved since early 2014 with one of the first coins that switched from PoW to PoS (Orbit) and we have made modifications
to the parameters to make that coin work better over the first months, so I have an idea how it is supposed to work, that is why I was
looking at Coin Control and trying to figure out when the wallet decides to re-combine inputs - I can see that normally inputs are always split during staking, but at times I see a larger than expected staking reward pop up and when I look at the inputs, there are fewer than I expect, so there are some times that the wallet decides to re-combine, but to me it appears to happen at random, not at a specific (low) value of input (which is what I have seen with other coins - a configurable threshold when it starts to re-combine, so you could manipulate how fast staking was happening without running into the max staking reward. This was sort of a game with the HyperStake coin.
So, I am still looking for a confirmation if the re-combination is at random or that there are certain fixed criteria when it is happening.
I could pull the repository and inspect the source code, of course but have no time to dig in right now.