This is the right kind of problem for McLaren to be having at this stage of the season, in my view. If they were to design a very reliable but middle of the road car pace-wise, what would be the benefit?
They - and any team that has ambitions of winning races - need to push the boundaries. If you design your chassis and PU under the same roof (whether literally in Ferrari’s case or figuratively in Mercedes’, Renault’s) it’s easier to ensure the two mate perfectly, with no issues, even if boundaries are being pushed; this is harder for teams like Red Bull and McLaren and I don’t think it’s any coincidence that both have faced a reasonable amount reliability issues - you have to push your design to the limits but, no matter the high level of cooperation with your engine supplier, you cannot design the two to work hand-in-glove - and they really have no other option than to ride this kind of knife edge if they want to succeed.
Red Bull have had longer with the Renault engine, so it doesn’t surprise me at all that McLaren are facing comparatively more issues during testing. The irony of shifting away from Honda but having more reliability issues than the new incumbent means it’s tempting to lay all the blame with McLaren, but I suspect you’ll see these much more quickly overcome.