I looked at the firmware for a bit and the device type and power limit can be conveniently set via SCPI:
SYSTem:DEVICE:PRODUCTUG:ID 1
SYSTem:DEVICE:POWERUG 300
Gives me 4 digits of resolution and a power limit of 300 watts on my SDL1020X-E. Note that the model string will not be changed by this by default (it's stored explicitly in the flash as well and can be changed with SYSTem:DEVICE:PRODUCTUG).
... my Hardware Version is 03-03-020.
Well I couldn't resist... my 1020X-E is now a 300W unit, with 4 digits of resolution....
The only trouble is now it has forgotten its model name (doesn't show on the info screen, or when getting an IDN?), my unit is hardware version 02-02-020
Originally it returned this: (SN obscured obviously)
Read Operation
Return Count: 56 bytes
Siglent\sTechnologies,SDL1020X-E,SDL1Xxxxxxxxxx,1.1.1.21\n
It now returns this:
Read Operation
Return Count: 47 bytes
Siglent\sTechnologies,\s,SDL1Xxxxxxxxxx,1.1.1.21\n
I haven't figured out how to correct this yet, I have tried sending the "SYSTem:DEVICE:PRODUCTUG" in various ways, including specifying the model explicitly "SYSTem:DEVICE:PRODUCTUG:ID SDL1030X" etc. without luck, I'm not at all experienced with SCPI so I'm not even sure if I am doing the command correctly.