Performance on recent laptops.

Yes, ASIO.

I am on a more "PORTABLE" laptop right now and don't remember the CPU number, other than that it is i7 with 12 threads, a base clock rate of 2.6 GHz and the standard overclock that typically hovers around 4GHz, 4.5 or so on some  programs.

So, it is no slouch. 
{Come to think of it - the CPU number starts with10
Alienware M17 R3 is the model, Dell is the manufacturer}

Anyway, in playing moderately dense midi files it goes into about a 2 second BUZZ once or twice per hour.

Off topic; if anyone has this model and has done a 16 to 32 Gig RAM upgrade please tell me how.
Removing the bottom panel seems to indicate that the RAM sockets are on the TOP of the motherboard, i.e. between the motherboard and the keyboard.

I am wondering if there is an easier way to access them than by taking the motherboard out and flipping it, e.g. can the keyboard be removed ?

Base speed should be more than enough. I would look elsewhere.
You might use this freeware to locate your issues
https://www.resplendence.com/latencymon

Same here in my laptop with the i7 7700hq, PT only sees up to 2801MHz, and Windows 3.6GHz.

Because this happens so infrequently, I wonder if this might not be related to a hardware issue. I don't think it is performance related. I would run extensive memory checks
first to see if you find any problems. Memory does fail and can cause weird problems when it happens.

In the modern Windows operating system, 32-bit applications live side-by-side with 64-bit applications. The operating system allocates up to 4 GB maximum memory space for them as needed. Having one or two 32-bit applications shouldn't cause problems because the 64-bit operating system knows enough to allocate the most memory to the 64-bit applications. The problem, however, is having too many applications running, will eat up resources, and having a hog application eating up the resources is a bigger problem.

The thing to watch for is CPU hogging. The Dell support software and the Alienware stuff really pegs my CPU badly even without Pianoteq running. After I noticed the system freeze, I checked the running tasks using Task Manager (Press CTRL_SHIFT_ESC), and the Alienware apps were running full bore. When I killed the tasks, the system became responsive. Dell's Support software too does this as well, and when the similar thing happened again, I ended up ending that task and this made quite a difference in performance.

Another thing too, remember this is a laptop and not a desktop. Laptop processors are different than their cousins the desktop version, and laptop hardware is also subject to a lot of power management well beyond the desktop equivalent. The laptop will idle down and turn off subsystems when things are quiet. If Pianoteq runs a lot in memory and taps at the CPU when needed rather than busying the CPU all the time, then those parts could be slowing down.

I agree there's an outside chance that there is an actual hardware problem, but I doubt it. I've run diagnostics, both built-in and separate and found nothing wrong.

The "support assistant" seems to take over at random times.
I find this particularly inexcusable on a laptop that is aimed primarily at the "Gaming" segment.
Sometimes the mouse becomes disabled for a second or so.

Not that I bought it for gaming, the graphics processor was attractive for my 3D modelling.

When I remember to suppress (KILL) the support assistant the problems seem to go away.
I just have to kill it after every re-boot if I want to run pianoteq.