I have no idea what you are saying because splitthreshold 24k or whatever I type in console gives the same value back:

splitthreshold 15000
22:36:01

{
"amount" : 2500.00000000
}
22:36:25

splitthreshold 240000
22:36:25

{
"amount" : 2500.00000000
}
And I cant find any proper documentation in the wiki what this does exactly. Maybe anyone want to link me or explain to me how this works.