Me-410 abilities as a bomber destroyer-Two Opinions

[kaki3152]

From the 492nd BG book "Fortunes of War:

"In the opinion of the crews the E/A pilots were experienced.Prior to a rocket attack from the rear the Me-410s were observed flying about six in trail. Leader would then waggle wings and the E/A would come up into line abreast and fire rockets. Note apparent ability of Me-410s to execute maneuvers usually credited to single engine E/As.Fact that crews report [Me] 410s continuing through the formation after attacking from different clock positions points to high performance characteristics for this twin engined E/A."

From the book "A Luftwaffe Bomber Pilot remembers" by Klaus Haeberlen
(September 1943)
"The B-17 had four engines, each with 1200 hp and two high altitude superchargers. The Americans could use their superchargers at 10,000 and 20,000 ft. thus maintaining the full power of their engines. Our Me-410 however, had two engines each 1750 hp and one high altitude (probably supercharger stage) supercharger which was brought into into play at 10,000 ft. This meant when we were at 20,000 ft altitude we only "half" the power of our engines. How could we sucesfully attack when our Me 410s was "sluggish" to maneuver and slow. My conclusion, was that with this disadvantage, an attack with rockets would not be succesful."

Later in the book:
"The Me 410 was just not capable of attacking the B-17s"

Was the Me-410s reengined with better engines by June 1944?
Was it beacuse ZG-26 was attacking B-24s that flew at lower altitudes?