Jonathan alerted me to this website, showing WHS with Portuguese influences:
https://www.unescoportugal.mne.pt/pt/temas/proteger-o-nosso-patrimonio-e-promover-a-c riatividade/patrimonio-mundial-de-influencia-portuguesa

Besides the ones we have in our connection, they name:
- Missões Jesuítas dos Guaranis
- Fasil Ghebbi, Região de Gondar
- Ilha Kunta Kinteh e Áreas Relacionadas
- Missões Jesuítas da Santíssima Trindade do Paraná e Jesus de Tavarangue

I could not find any evidence on this. Any ideas?

Gondar Ethiopia is "well known" for having Portuguese "influences" because of the role of Portuguese soldiers in helping the rulers. The castle certainly seems to look a bit "Mediaeval European"!
I think it would be a bit "too far" to claim it as having "been built or owned by Portuguese"
See - http://www.ethiopiantreasures.co.uk/pages/gonder.htm

Re Kunta Kinteh etc
The village of Juffureh within this WHS has a ruined Portuguese Chapel - the Portuguese were the first nation to set up a station there.
See - http://afrotourism.com/attraction/portuguese-chapel/

With regards to the Jesuit missions, it seems to me that the inclusion in the website Els mentions is rather due to the fact that the area belonged to Brazil (and thus to Portugal) - or was at least in contention between the Portuguese and the Spanish crowns - rather than due to any special Portuguese influence.

Funnily enough, while looking for infos on it, I stumbled upon another heritage list - the Mercosur association has apparently started to create a list of Cultural Heritage of the Mercosur (Info from Brazilian cultural entity) which, so far, only includes a Bridge between Uruguay and Brazil, the various missions (to the Guaranis, the Chiquitos and the Moxos) as well as a type of poetry as immaterial heritage.