No, not with your X7 I'd suspect. Stay with KT88s. Here is why...one other thought.
@hvuck did you happen to notice your X7 amp designed for KT88s weighs 22.5kgs? Now compare that to the new Muzishare X10 amp designed for KT150s, weighing in at 35kg. Wonder why there is a weight difference b7 between your X7 and the X10 model amps? Worth researching more, this may be a sign. Bigger transformers, maybe.
The KT150s can operate with higher plate voltage which typically requires larger and heavier transformers. Seeing this trend over the past two years with amp designers now coming out with weightier amps to run KT150s properly, in their window of optimum operation so to speak.
RE: KT150s
My amps are designed to run KT150s, sometimes they can be so clear and transparent, and while it sounds great with a little more low end, there is more top end too - ruthlessly transparent some times. Gives the perception of less bass sometimes too. Totally neutral. Some love this. There are times I wanted to go back to a KT88 sound for added midrange warmth. Ended up with KT120s as my alternate set. If you must, maybe sell your X7 and buy the new X10 which runs KT150s natively if you must have KT150s. Another angle to your question.