Questions

Hi, there.

What you can do is to draw your labels directly on your columns. You need to subclass your RenderableSeries, override internalDraw method, create your SCITextLabelContainer and provide a proper drawing frame, like this

import SciChart.Protected.SCIRenderableSeriesBase

let xAxis = SCINumericAxis()
xAxis.axisAlignment = .left

let yAxis = SCINumericAxis()
yAxis.axisAlignment = .bottom
yAxis.flipCoordinates = true

class LabeledStackedColumnRenderableSeries: SCIStackedColumnRenderableSeries {
    override func internalDraw(with renderContext: ISCIRenderContext2D!, assetManager: ISCIAssetManager2D!, renderPassData: 
ISCISeriesRenderPassData!) {
    super.internalDraw(with: renderContext, assetManager: assetManager, renderPassData: renderPassData)

    guard
        let rpd = renderPassData as? SCIStackedColumnRenderPassData,
        let xCoords = rpd.xCoords?.itemsArray,
        let yCoords = rpd.yCoords?.itemsArray
    else {
        return
    }

    for i in 0..<xCoords.count {
        let x = CGFloat(xCoords[i])
        let y = CGFloat(yCoords[i])

        let textLabel = SCITextLabelContainer()
        textLabel.text = "\(rpd.yValues.getValueAt(i))"
        textLabel.padding = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 5)

        let size = textLabel.sizeWithMargins

        // set y to x and x to y because xAxis.axisAlignment == .left and yAxis.axisAlignment = .bottom
        let frame = CGRect(x: y - size.width, y: x - size.height / 2, width: size.width, height: size.height)
        textLabel.onDraw(with: renderContext, assetManager: assetManager, inFrame: frame)
        }
    }
}

See the screenshot.
Let us know if it works for you.
Thanks in advance