In this case, Ofcom's stated goal (which I admit may be different than their actual goal) is to get overseas companies to comply with their rules.
I think you may be giving them too much credit. You're essentially saying that their real goal is to get an ISP block and everything they are doing now is performative to get to that real, unstated goal.
On the other hand I may be underestimating them as, to me, they just seem like power-tripping troglodytes.
I don't think the fine is performative. It's just the first sanction that gets applied. I don't understand why you think that's incompatible with Ofcom's stated goal.