The main premise of progressivism is that advances in technology and social connectivity lead to an overall increase in societal welfare.
What this means is that any policy / platform that strives for social reform in a positive direction can be labelled as progressive, though most surely the line would be drawn at supporting platforms that are not well liked by the traditional antithetical political hegemony. Candidates that are also happen to oppose policies such as Universal Health Care, prison reform (including police and justice system reform and legislature reform), campaign finance reform, dark money in politics are not progressive due to their normalizing of a (perceived) misaligned status quo
Other issues in my opinion are not important (or not as important) because they do not actually lead to social reform. It's all fine to be on the same side for climate change futures,
calling for 5T$ to spend fighting climate change, but when your policy doesn't support manhandling campaign finance or dark money and you actually get
500k+$ in oil lobby donations, then you can't call yourself a progressive candidate and shouldn't actually be seen as such.
When you mention that you're socially aware enough to talk about reparations and abolishment of death penalty but at the same time you also
fight to keep people in prison after they are proven innocent and defend the death penalty in California court, then in my eyes you can't possibly be a progressive candidate.
Implicitly I think people that don't argue for reforms on justice, reforms on campaign finance, and health care reform, then you can't possibly be labelled as a progressive. Those to me are the 3 pillars that constitute my idea of progressivism, as I think campaign finance reform will in turn naturally lead to efforts to combat climate change, efforts to control the gun lobby, and address the drug war; similarly justice reforms would target police brutality, inequal action taken on laws, drug reform, and class warfare (in courts); lastly health care reform is hugely impactful for economic uplifting.
edit: to be clear i think that if you aren't calling for things like prison reform or the above then you implicitly acknowledge the normality of these issues and thus are not progressive.