The problem isn’t that regulations exist. The problem is that they are defined in a way that reasonable work arounds or alternative pathways do not exist for situations like this. 270 engine families for 9 engine suggests that the designs may be small variations that would not significantly change the emissions between them. The bureaucrats should waive off some requirements here.

The other alternative that I can think of is that experimental engines get an exception to be not certified for X miles of operation. Once the candidates are chosen for mass production, mandatory certifications can be introduced. Even if your new design doubles the emissions for some reason, over 100000 miles, that’s barely a drop in the bucket. For reference, double the emissions for 100000 miles is roughly equivalent to having an extra semi on the road for a year, which is nothing.

We need more information. How does this work for internal combustion truck engines?

Is the regulation well intentioned poorly designed? Is it anti-competitive gatekeeping drafted by lobbyists? Is the author misrepresenting something? All of the above? Hard to say.

You cannot separate the idea of regulation from their harm because they are inherent to the concept. A system so complex and dynamical as human civilization is beyond our ability to correctly ascertain the outcome of interventions, especially those imposed from the top down. In other words, we're likely to do more harm than good by imposing interventions because we cannot accurately predict their outcomes. Which is why they often have paradoxical effects. Rent control is a fantastic if trivial example of such.

We know central planning doesn't work, yet we are inclined to do it anyway under the false notion that it's better to do something rather than nothing.