Processing one my latest holy grail timelapses with LRT 4.6 I'm facing a serious problem with the HG leveling on the sunrise part of the timelapse. The photos are taken with qdslrdashboard and show reasonable exposure. Going through the visual workflow as usual defining some keyframes I realise that there are some heavy spikes in the HG leveling graph. None of the three adjustments for HG could significantly reduce the spikes. Processing visual previews with thesse spikes gives huge spikes in exposure that were not here before. The exposure of the keyframes is alright and I tried to define keyframes around the HG ramps with no improvement. Any ideas what I could do?

You have adjustments on subsequent frames, this is too close. There is a reason for the minimimum distance between adjustments being set to 3 shots in qDslrDashboard by default (transfer every 3rd image in the settings). Obviously you changed this. Combined with the interval that's way too long (90 seconds!) this gives no good results. The holy grail wizard needs at least 2 or 3 frames between each adjustment, otherwise it cannot detect the natural progression in the change of brightness and will deliver results like that, I'm sorry.
To save the sequence, you could try to redo the sequence and skip the holy grail wizard at all. Then just use the visual deflicker and some refine steps. But of course, there will be no guarantee that this delivers a good result.

Next time: set the qDDB Settings to transfer every 3rd image only (like by default) and use shorter intervals! 90 Secs is way too long for that kind of timelapse. I'd go for maximum (!) 20 seconds, preferably shorter - otherwise is won't be nice to watch anyway.