Yes!! You can get 6x6 mm tact switches that can have a button cap snapped on. Here is one example: E-Switch TL3301SPF260QG
The key is to look for parts that have the square actuator. This keeps a button cap oriented in the correct direction and the post feature of the actuator allows the cap to snap on and stay on. I have used this type multiple times on projects but also find that right angle versions work nicely when the switches must protrude through a front panel that is next to the circuit board.
The right angle type that I have used (E-Switch TL1105JAF250Q) look like this. Through hole is used so that there is a rugged switch mounting and good alignment of the button to holes in the front panel. The caps I use for these are designed to fit through a square hole which are easily cut through a front panel made of aluminum with a laser cutting process.
Here is an example of one product I did that uses the right angle switches. They protrude through a front panel that is also covered with a die cut Lexan overlay. The design has the buttons protrude only enough so that the push and feel is just right. Not sticking out more than maybe about 40 mils or so.