The Auto/Engine combination is mapped to let the auto climb up to the highest gear at lowest revs as fast as possible to reduce fuel consumption/emissions. As they control the combined map of the two this is practical however when you put the MkI human in path there is a pattern that tends to hold lower gears and avoid labouring the engine?

Any changes to the map will be visible to engineers who inspect it which will bin your warranty. It has been a common issue on turbo engines for a long time now.
Also don't forget that whilst they appear to be the same engine with different bhp there is often a different piston/turbo/boost control valve for the higher powered ones which is not so visible?

Don't take that as "I think people who adjust boost etc are evil" quite the opposite. I find the economy minded engine map on most modern cars a royal PITA. It makes the throttle feel like a dead cat. You then have to hit the sport button to enjoy yourself again. Thems the rules, thems the results. It is totally possible I might have done some of my cars in the past.

Oh, don't forget your insurance. If there is an RTA they WILL inspect it.

Everyone loves a Morgan. Even me, unless it's broken again.