Is it possible to insert a rounding?
Let me explain:
I have this item in watts, I would like to transform it into KW, rounding up so that if it shows 9 watts, 0 kw is written
item=TeslaPowerwall_Instanteous_Solar_Power label= "Fotovoltaico Totale Tesla [%.0f W]" icon="solarplant"
I think you need to explain a bit more exactly what you want.
Do you want it to always show the unit in kw? Just change your format from W to kW
Do you want it to dynamically show W or kW depending on a range? You can do that using script transformation and have it do whatever you want based on any criteria.