Highcharts: change timeUnit thresholds - highcharts

Question

I'm looking a way to override Highcharts.timeUnits, which seems the array defining when jump from a unit to another unit. (It's not as simple as that in the source code, but ...)
Why ? Because my need is the following :
I have timeserie data, by 15 minutes, for 3 years.
I want a zoomable column chart (I use highstock in practice), where I have 1 column by month with a given zoom, 1 column by week when I zoom more, then 1 by day, 1 by hour and then 1 by 15min
In the idea, I use plotOptions.series.dataGrouping.units to define these parameters:
units: [
[
'minute',
[15]
], [
'day',
[1]
], [
'week',
[1]
], [
'month',
[1]
], [
'year',
[1]
]
],
But Highcharts use its own rules to jump from an unit to another one, and I find these rules not appropriated to my use-case (switch is too "early", I think)
I can change a bit the behaviour by modifying groupPixelWidth but this is a last resort, because it behaves strangely anyway.
Here is an example. If you click on the various time scales, you'll see that the the timeUnit choosen are often not appropriated.
For example choosing week or with a span from Nov 5, 2018 to Nov 26 2018 : you get data displayed by hour, but data by would be more readable, etc.
https://jsfiddle.net/f4wma38h/

Answer 1

so you are looking for 15 minutes & hour zooming in your chart am i right?
xAxis: {
type: 'datetime',
minRange: 15 * 60 * 1000
},
rangeSelector: {
buttons: [{
type: 'minute',
count: 15,
text: '15m'
}, {
type: 'minute',
count: 60,
text: '1h'
},.....
make the xrange minvalue as 15 in milliseconds & in range selector add the button for 15m & 1h
jsfiddle:https://jsfiddle.net/karnan796/f4wma38h/11/