How come you said "If only you use an full 13a power cord on the much lower rated device like 4.5a will result in fire risk due to the fact that the 13a fuse won't blow even when the device is under overloading status"
If a device designed for 4.5a max only, it should also comes with a fused power cord with 4.0a or maybe max 4.5a but never a 13a fused power cord.
The 4.5a fuse expected to blow when the device draw current exceeding (ad normal operation or malfunction) the designed 4.5a to protect the device. Using a 13a fused power cord will result in the device severely overloaded but the 13a will not blow when the device malfunction. The 13a fuse will blow only when exceeding 13a, not at 4.5a.
Got it?
It seems like 13A power cord and the device only use 4.5A, is similar to my blower situation 16A power cord on 2.61A device, how come you said "will result in fire risk due to the fact that the 13a fuse won't blow even when the device is under overloading status"
Totally different from your case, please ignored this issue, not relevant to your case here.

