In terms of an open lid CAI sealing or not sealing against the hood liner...
It's very easy to test how well your own open lid CAI seals.
Simply smear a thin layer of shaving cream around the top rubber gasket of the airbox.
Then close the hood and open it.
If you see the shaving cream on the hood liner, then it is touching and sealing.
If it is not, then simply add another layer of rubber sealing (self adhesive type) on to the top of the existing rubber seal.
If you are really concerned about your open lid air box not being as efficient as a closed one, you can always cut to shape a piece of clear transparent Perspex or acrylic sheet of about 5mm thickness, and attach it to the top, so you can still see your nice pod filter.
Where people have issues, is when they remove the insulating under hood liner, creating a large air gap between the top of the air box and metal hood.
Also, removing the headliner, means less heat insulation for the box itself, with just a thin sheet of metal above it.
The other thing people forget in the open lid air box equation is this...
An open lid box that does not seal, will not retain as much heat once you start moving, as cooler air comes in through the main front grille opening, any hot air in the box will rise to the top and vent into the engine bay, being displaced by cooler air.
The temperature of the air box plastic construction will also cool quicker than a sealed box.