If you are unfortunate enough to not be sailing in beautiful conditions, and you want to consider heaving to, you need to think through the decision on where and when to do that.
An isochronal weather routing solver is an optimizer, trying to always find the fastest paths, which satisfy all of the constraints, between the start and target points.
However, if the solver is noting that the forecast conditions will exceed the maximums you have set and that it must heave to for a duration, do not take the timing and path to the hove to location as recommendations.
Also, note that whenever you are allowing LuckGrib to consider the option of heaving to, you should also be having it generate solutions with and without heaving to. If a path is available which avoids heaving to, you should carefully consider it.
Recall this goal of the system:
Once you make the decision that you will heaving to, for some duration, to avoid sailing in some extreme conditions, you should consider if there is a change of direction that will position yourself in a more favorable location.
As discussed soon, there are some simplifying assumptions made for the vessels location while hove to. You need to consider if you should seek additional sea room while it is (relatively) easy to do so. Your vessel will drift somewhere while hove to. Having additional sea room may be worth considering.
There may also be a possibility of moving more quickly through the extreme weather, or choosing a less extreme portion of the weather feature.
Do not blindly follow the WR path as a suggestion on what to do. Carefully consider changes of direction to improve your experience while at sea.
Another factor to consider once you have decided that you will soon heave to is to start considering how to change your sail plan prior to this. The weather routing solver is always trying to optimize, finding the fastest way to go somewhere. In this case, it is finding the fastest way to get to the area where you heave to (and then through it to your destination.) You should consider the option of slowing down as much as you can, before you encounter those winds, and see how that may affect the outcome.
Carefully examine the weather system. Is there an advantage to slowing down before heaving to? Will doing so help by avoiding some of the strong conditions or would they be worse?
Rather than heaving to, will you be able to reef heavily and continue sailing slowly? What would the effect be of sailing slowly downwind for the duration of the strong winds? How much sea room do you have?
Once you have made the decision to heave to, use the path only as a general guide.