I also found this chart for WB06 and reply to a message from Fermentis at Probrewer.com. Pitch rate and temperature for the desired ester level. I like the clove with banana in the background.
The clove aroma/flavor is natural to the WB-06 as it is a POF+ yeast releasing the 4-VG and phenolic compounds.
Please find below the impact of pitching rate and fermentation temperature on the production of isoamylacetate, the banana flavor component.
From the above, we indeed notice a better expression by stressing the yeast and dropping the fermentation temperature; and as reducing a bit the pitching rate.
Of course, the above graphic is an extrapolation of observations we made for fermentations under a range of conditions but we didn’t get to the extremes…
There is only so much you can do.
So, yes please try moving down to 20°C first and maybe even a bit lower, keeping your pitching rate unchanged as you might have a bit more difficult end of fermentation.
In any case, at lower temperature your fermentation will obviously be a bit longer.
After fermentation, we would also recommend lagering at even lower temperature if you have no other issues; down to 4-5°C.