In my opinion, offsetting and removal are often mixed up or interchangeable words. Offsetting is Carbon emissions neutrality. Removal is Carbon-negative. In the case of puro.earth, they are using, and I don't like the acronym, called CORC (similarly named like Nori's 'CRC'), which stands for Carbon dioxide (CO2) removal certificates. This is good for businesses eg.tech giants like Microsoft because you can be removing Carbon while you're using your production line to do whatever you want to do with it. In the case of ECHO2/'Holla Fresh' herb production greenhouse, it was providing services (heat/power) while producing biochar (another service), which not only offsets Carbon pollution from the fossil fueled system, it is also removing the Carbon from the atmosphere/climate via woody waste. So it's both offsetting and removing CO2 equivalent emissions.
In the case of the Kon-Tiki 'Rolls', although there are less cogeneration opportunities than the ECHO2 at this stage (I'm waiting for TEGs to go down in price), the biochar produced when used in a growing system is still offsetting Carbon by reducing the amount of fossil used in the system, which may include no-till agriculture (using compressed air biochar injection), less pesticides and herbicides and less fertiliser (most of these use fossil in their production eg. Natural gas to produce fertiliser). Carbon reduction is definitely happening since the biochar is taking Carbon indirectly from the atmosphere via biomass feedstock and locking into a supply chain or directly into soil. I'd be interested to learn what people think about any of this!