im sure a lot of us newcomers have the same Question/
why dont you try it and post back on whether it passed or not?, go a little before your expiry date if it fails get it fixed if it passes please post back.

LP from what info i have its not about cosmetic appeal of the car, for a small dent (maybe self inflicted) the car will pass technical but it will fail legal because they dont khow whether it is actually self inflicted or you bumped into someone elses car while say parking ....in which case you are legally liable to the other car owner.
Not that fixing it solves the problem with the other owner or brings accountability , but thats the logic used