Scottish clubs can sign players from the European Union as normal, in the January transfer window, after the Home Office agreed to delay new rules.
With the brexit transition period to end on 31 December 2020, it was thought the points system adopted, by the English FA would be introduced in Scotland.
That would have made it harder for uncapped players to move to the SPFL, but a request from the Scottish football joint response group for the new rules, requested the new rules be put on hold, has been accepted.

I was thinking could there be a loophole, where a Scottish club have close ties with any English / Welsh clubs, the Scottish team signs a player, then loans him to a English / Welsh team, but surely the English FA will be watching any such thing happening.