Government plans to prevent tuning

That proposal seems clearly targeted at DPF and GPF removal. I don't see how it affects ECU remapping or part uprating as long as it doesn't "bypass" of "defeat" another system.
A few years ago this might have concerned me but I couldn't justify buying another ICE car now - my next car will be electric.

Those "CO2" neutral designs are based on the idea that the emissions from the ICEs (which are reduced but certainly not zero) are recaptured so that the whole lifecycle becomes net zero. However there are various processes which make the whole system less efficient than simply generating electricity from renewable sources and putting it directly into the batteries of electric cars. I imagine that the various schemes will run in parallel and some will increase in popularity and others will decline. And as Dave points out, Government legislation will kill off the ICE market anyway no matter how the fuel is created.