As you will know, if only from researching your article on the Combat of the Côa, on the Portuguese side this is very difficult terrain.
I’m interested in these issues relating to logistics myself, so find all this fascinating.
Settlements then, as now, can be quite isolated in what continues to be a quite thinly populated region and often these settlements are in very isolated rural hinterlands.
For example, it looks like Açores is an aldeia (small settlement) in a freguesia (equivalent of a rural ward) of the larger settlement (small town) of Aguiar de Beira: equidistant between Trancoso and Lamego.
See Luiz Cardoso, Diccionario geografico …
St. Jago (Sāo Tiago or Santiago) is a common name and I could find a few on google maps in Beira Alta. A good quality, large-scale map would be useful to identify these various settlements.
There is a Santiago, just east of the modern N. 17 and to the North West of Seia.
Gouveia with distribution from Linhares makes sense in terms of distance. However, as all the other distribution points are larger settlements and Linhares is even more isolated in, what is today, the national park of the Serra de Estrella it seems a little strange. But is it connected to Beira Baixa by the Estrada Nova – which might make some sense from the point of view of provisioning and other Portuguese troops?
Fraxedas could possible be Freixedas which is equidistant between Trancoso and Pinhel.
Alverca is quite close to Celorico.
Sandomil and Sampayo (Sāo Paio), if the ones I found are correct, are also a little strange in that they are quite far back from Welington’s line and their allotted distribution points are to their north.
I think you will find most of the remainder in the diccionario, I found quite a few …
Alverca, p. 399
Baraçal and Freixedas p.45
Sandomil p.376 (quite possibly this one, as mentions the Alva)
Hope the above is helpful