When the processor is well soldered to ihs, it is best not to remove it. Heat is easier to extract using a larger surface. It is better to polish the ihs to improve the contact.
As for the current capacity to cool 250w, it all depends on what you mean by "easily" cooling.
For a cpu under burn at 70°, something really effective should make a delta of 10-20° (max) with water. Something like 50-60°
Water out of waterblock, pipes and radiator(s) must be hot, let's see the current heat transfer waterblocks:
The hotter the water (of course keeping a minimum flow) the higher the performance. With 36.5 ° as delta for the best, there is still a lot of room for a real performance evolution!
One must think about transferring the heat throughout the block before looking for a way to cool it.
Just as the cpu must be welded to the IHS, the top and bottom parts of the waterblock should be "welded".
As we have to open it to clean it, it's impossible to have a block in one block. The research should be articulated in this direction.