[MrFlippant]

I've never tried that feature, not sure I can trust it 100% to decide where the thick layers need to be 

I'd say I'm about 50/50 with respect to how many prints I use the automatic versus how many I either set manually or adjust after automatic. The tools to manually set, or adjust, are quite robust. In some rare cases, I'll use the Height Range Modifier option to set a layer height right up to a specific layer, and then a new layer height from there.

The tools really are quite powerful if you spend some time to play with them, beyond just setting a specific layer height for the entire print.

That said, some prints need a fine layer height from start to finish, so setting variable height saves nothing. The example in the OP is probably one of them.