you fail to understand what testing and installing an engine means
if you expect Mclaren to just go ahead and fly around the track you seriously don't know squad about F1 nor engine technology. Go ahead and check out last year's testing, take Mercedes for example. 'Broke down' after a couple of
corners. Wanna know where the Merc engine ended? ah yes, win win win and win. Did i say win?
If any, this is a good sign, showing they complete several laps, compared to the struggle of last years manufacturers.
this is actually Honda's 'first' real test.
It sounds exactly to what they're doing; making the engine run in several testing modes to discover the wear, the load,
the effects, and how to correlate simulation data to real life data without blowing the engine up. Trying various engine maps to see how they can make the turbo respond at the best way possible, combined with the energy recovery systems.
Checking how all electronics behave to the total package, how the fuels, oils, and fluids respond to the movements.
It's actually all good.