Top loading CD Player clearances

I am currently considering replacement of my Transport/DAC combo with a One-Box digital front end.

I should preface this question by saying I prefer front loading players for my placement application, but there are a couple top loading players I would like to consider due to their capabilities, the front runner being the Reimyo. However, I have never owned a top loading CD player, and do not understand how much room is necessary on top of the units in order to open the door, comfortably insert or remove a CD, and close the door without difficulty.

Any comments about minimum space requirements above the unit in order to see and physically pull this action off without trouble/aggrevation would be appreciated. FYI, there is a shelf which cannot be removed located above the location where the unit must sit, but I have some latitude in how low the CDP can be placed below the shelf. If I go too low though, I start running out of adequate space for remaining components. Any advice in this regard would be appreciated.

Thanks in advance.