Yikes, Greg!
Seems you are on a roll with regard to property issues that are somewhat borderline.
I can see the argument for making this subject-to, but I'll propose an argument that concludes otherwise....
1. The condition impairs the overall functionality of the home. Garages (I presume) within that neighborhood are expected to have garage doors that work.
2. While affecting the functionality, it doesn't (I presume) affect the habitability of the residence. The plywood barrier doesn't affect the ability to occupy the home.
3. This is (presumably) a temporary condition; one that is easily identified and easily remedied. The cost and scope of the project is well defined.
4. If the subject were to be put on the market and sold, it is very safe to conclude that the impact on value is the cost to install a new garage door (unless that market is particularly "hot"; then it may not have any impact).
A temporary condition, easily remedied, which does not impact the safety or soundness of the structure or its ability to be occupied. Nonetheless, as-is, it would have an impact on value. That impact is easy to identify and account for in the analysis.
I'd identify it, discuss it (as I have above), conclude that it does not affect the safety or impair the occupancy of the home. I'd state that it has an impact on market value (as-is) and adjust for that impact in my analysis.
If the UW has an issue, they can come back and ask me to make it subject-to. Easily done; the impact on the analysis would be to remove the adjustment applied for the garage door condition. That may impact the final value opinion, but not necessarily on a dollar-for-dollar basis: if I've rounded my value conclusion to the logical price-point within the adjusted range, based on that rounding scheme, the consequence of fixing the condition may not dollar-for-dollar. Example: Assume I've rounded to the nearest $2,500. The garage door costs $2,000 to replace. My value may be concluded at the next rounding point (which is $500 more than the impact on value of fixing the garage door).