from what I read, Frederiksen has also shifted the party to the left economically

She really hasn’t, no.

she implemented earlier retirement and higher pensions

For select professions only, after unsuccessfully trying to make the work week longer for EVERYONE to ensure that nebulous “growth” that Neoliberals and Conservatives alike are so obsessed with to the detriment of those areas of society that are already the most underfunded.

financed by increasing corporate taxes by 4% and taxing corporate real-estate appreciation

That one slipped by me, though, that’s an excellent step in the right direction! Tiny, but still excellent.

subsidized dental healthcare with a goal of completely including it in free public healthcare

That one’s true, but a concession to the left wing of her coalition so they’d accept her continuing as Prime Minister rather than something she ever wanted herself.

taxed carbon at $40–$100 per ton (incl. agriculture)

That’s a good start too.

campaigned on free public transport (no fare) for those <22.

Another concession to the Left, specifically an important policy for SF (Socialist People’s Party by name, but long since more of a social democratic party picking up the voters the nominal Social Democrats left behind when they drifted right)

she also campaigned on some wealth tax this year, which is what gave me the impression, but chickened it out for the other liberals

Fixed it for you.

she considers anti-immigration as being economically left

Which is some demagogue nonsense leading to a lot of unnecessary hardship for the people in general, not just the immigrants directly targeted.

due to being cheap labor for capitalists that displace unionized workers

The left wing solution to which is to help the immigrant workers being exploited and penalize the employers exploiting them.

Hurting immigrants to (pretend to) help unions is some of the most insidious and harmful demagoguery ever.

is another reason why I hate economists, all of which reduce humans to statistics

And often misrepresent the statistics too. Immigrants (especially those on political/humanitarian asylum) are a huge net POSITIVE for the host economy, most of all low income people.

excluding the anti-immigration

No thanks. Immigrant lives matter.

it seems economically left to me.

It mostly isn’t, though.

As I’ve conceded above, her economic policy hasn’t been UNIVERSALLY bad/right wing, but most of it has been and continues to.

a search (a.k.a. well-sourced passages from Wikipedia) claims Sweden’s socdems’ (not to be confused with Swedish Democrats) position on immigration has not changed

Fair enough. Being Danish myself, I know much less about them than I do about the Danish ones.