If you have a dedicated line to your amp, and your amp has say 6.3 amp fast blow fuses in it, would putting a low current 6 amp breaker in your panel do the same thing?
Panel mount: The issue is that a magnetic breaker replacing a fuse needs to be dedicated to a single the component, just like a fuse protects the component. OTOH, the breakers in your panel protect the line - i.e., a 20A breaker breaks when current on the line exceeds 20A at which point a single component might already be fried.
Fuse holder mount: The magnetic breaker is quite a bit larger than a fuse holder. If you are asking about retrofitting existing equipment the easiest method would be to use something like the SDFB. In looking at retrofitting my SMc amps, it would have required cutting a hole in the back plate of the metal case and then rewiring the fuse holder and IEC, all of which I was comfortable doing myself. The problem was having to move the main board and disconnect several parts to make room to perform the work and at that point it became easier, less invasive, and less risky to incorporate a solution that was exterior to the amp. SMc uses the breaker to replace a fuse in their new equipment, and in their upgrade work. However, the breaker requires a larger hole in the case than a fuse holder. The breaker can also take the place of an on/off switch as it does in my SMc DAC-2.
Exterior box mount: I believe the easiest DIY opportunities for existing equipment are either a separate external box (like SDFB) or perhaps mounting the magnetic breaker in a gang box or separate small breaker box wired directly to the power line feeding the duplex where the equipment is connected, which is what I plan to do. The key is providing one breaker for each piece of gear so every outlet would need to have its own breaker. My two amps are fed from a single dedicated 30A line and each have a 10A fuse. I plan to mount the two 10A breakers just in front of the duplex, with each breaker feeding one of the two outlets in the duplex. Each outlet will have its own dedicated breaker. The outlets in my Furutech duplex will need to be separated from each other by cutting the tabs on the outlet and then each outlet will need to be individually wired. The breakers are basically an in-line switch wired on the hot side.