Still don't see anything that requires weather at your destination to depart somewhere else IFR
Now I'm confused

. Here's my logic:
§135.213Weather reports and forecasts.
–(a) Whenever a person operating an aircraft under
this part is required to use a weather report or
forecast, that person shall use that of the U.S.
National Weather Service, a source approved by the
U.S. National Weather Service, or a source
approved by the Administrator. However, for
operations under VFR, the pilot in command may, if
such a report is not available, use weather
information based on that pilot's own observations or
on those of other persons competent to supply
appropriate observations.
To me, this indicates that the only operations where you DO NOT need your destination's weather report are:
- VFR
135.213
•(b) For the purposes of paragraph (a) of this section,
weather observations made and furnished to pilots to
conduct IFR operations at an airport must be taken at
the airport where those IFR operations are conducted,
unless the Administrator issues operations
specifications allowing the use of weather observations
taken at a location not at the airport where the IFR
operations are conducted. The Administrator issues
such operations specifications when, after investigation
by the U.S. National Weather Service and the
certificate-holding district office, it is found that the
standards of safety for that operation would allow the
deviation from this paragraph for a particular operation
for which an air carrier operating certificate or operating
certificate has been issued.
To me, this indicates that you need A057 if you're going to conduct IFR operations to a destination without approved weather.
Lastly, you have 135.219:
§135.219IFR: Destination airport weather
minimums.
–No person may take off an aircraft under IFR or
begin an IFR or over-the-top operation unless the
latest weather reports or forecasts, or any
combination of them, indicate that weather
conditions at the estimated time of arrival at the next
airport of intended landing will be at or above
authorized IFR landing minimums.
So to me, the FARs (not specifying scheduled vs. unscheduled) explain that you need destination weather unless you're VFR or have A057. Otherwise, you're not in compliance with 135.219. I certainly could be wrong, but that's how I'm interpreting the regs.
I don't see any reference to IMC operations, just IFR... maybe I'm wrong, but this tells me that, even if it's CAVOK, you need weather at the airport indicating such if you're on an IFR plan (unless you have A057).
Looking forward to some other opinions!