It's for the Scottish. It's in Iran's interests for Scotland to become independent because that would enforce change on the United Nations Security Council. The UK ceases to exist and loses its veto, then what happens on the UNSC after that is anyone's guess.

Apparently X is entirely blocked in Iran unless using a VPN.

Perhaps they mean to influence Iranians who activity circumvent internet restrictions :-)

Not Iranians - what would anyone gain by influencing Iranians' views of Scottish nationalism? My experience has been that people outside the west barely know Scotland exists and are not going to care about it anymore than the average Scot is likely to have strong feelings about Laos.

It may be aimed at Scots but sometimes be done too blatantly so slips into the implausible. It may be aimed at influencing just those prone to conspiracy theories - who might be few but more likely to extreme actions.