The smi_paths
file isn't saved per-profile, so unfortunately you can't use different profiles to solve your problem, at least not without a Wireshark enhancement to support this. You can file such an enhancement request on the Wireshark Bug Tracker if you like.
Alternatively, you might be able to accomplish this by specifying the path as a Wireshark option when Wireshark is started. For example, on Windows I tested this with:
wireshark -o "uat:smi_paths:\"C:\x5cWireshark\x5cmibs\""
If there's already a path specified, the default on Windows being C:\Program Files\Wireshark\snmp\mibs you will likely have to either remove that path first using Edit -> Preferences... -> Name Resolution -> SMI (MIB and PIB) paths -> Edit -> Select entry -> click [-] or just delete/rename the smi_paths file, as this command-line uat option only appends the path, so the first path is still going to be active.
Note that this does come with an annoying side-effect in that Wireshark pops up a dialog indicating that, "Wireshark needs to be restarted for these changes to take effect". At the moment, I'm unable to test whether that's really true or not (i.e., that you have to save the preference and restart Wireshark), but if that is the case, then obviously this method won't work all that well.
All in all, the best way to work around smi_paths not currently being saved per profile might be to wrap Wireshark in a script or batch file where you first copy the desired smi_paths file to your Wireshark personal configuration folder and then start Wireshark. For example (again, on Windows):
@echo off
set batfile=%~nx0
if /i ["%~1"] == ["-h"] goto usage
if ["%~1"] == [""] goto usage
if not exist %1 (
echo File not found.
goto :eof
)
move /y %APPDATA%\Wireshark\smi_paths %APPDATA%\Wireshark\smi_paths_save
copy /y %1 %APPDATA%\Wireshark\smi_paths
wireshark
move /y %APPDATA%\Wireshark\smi_paths_save %APPDATA%\Wireshark\smi_paths
goto :eof
:usage
echo %batfile% ^<file^>
So, after first creating the various smi_paths files containing paths to per-manufacturer mibs, you could invoke the batch file as:
ws_smi_paths.bat manuf1_smi_paths
or
ws_smi_paths.bat manuf2_smi_paths
… and so on.