Actually, that's sort of the reverse: VOY "Pathfinder" establishes that Barclay estimated warp 6.2 as the average speed of the ship in the first five years of her odyssey, and somehow this estimate helped him create three different scenarios for where she was (even though he was not aware of several very long jumps the ship had performed since the last contact with her) - and one of those three scenarios got the position exactly right! The speed of 438 ly/y would have been worked backwards from that average speed of warp 6.2 by using the Okudaic scale.You mean 438 light-years per year, according to Star Charts. That would place her cruising more around Warp 6.2 according to the TNG scale.
We can probably estimate the course of the ship to have been a beeline, despite all the minor detours and loops. The average speed of the ship when including the big jumps would have to be very high indeed, as it would be ten times faster than Janeway's original "Caretaker" estimate of "even at maximum warp"... So the average speed of warp 6.2 must refer to travel excluding the jumps. Or else warp 6 is a hundred times faster than the Okudaic chart suggests! (Not to mention that warp 6 would also be ten times faster than the top speed of the ship, which we already know is in the high warp nines. Doesn't compute...)
If Barclay was correct in his estimate, then we can interpret this data two ways:
a) Whenever the ship moved at warp between jumps, the speed averaged to warp 6.2.
b) Whenever the ship was between jumps, never mind whether at warp, impulse or standstill, the speed averaged to warp 6.2.
It would seem at first that option b must translate to much higher warp cruise speeds. But we can't really tell the difference, because the only solid data we have is the average speed including the jumps, and the contribution of the non-jump periods to the total speed is so negligible that a and b appear more or less equal.
Timo Saloniemi