There are many other individual challenges that Frumin has yet to rule on. It's pretty difficult to tell which way the guy will go, though he does work for Democrats. I delved into the Senate Parliamentarian's politics in this story a few weeks ago.
Then, of course, there are the overall challenges by legislators like Rep. Michelle Bachmann (R-Minn.), who just wrote on this blog about her plans to challenge the constitutionality of Obamacare as a whole.
Surprise: Politifact Rates Hugh Hewitt's 'Obamacare Death Spiral' Statement as "False"
Sanctuary City Mayors To Trump White House, AG Sessions On Funding Threats: See You In Court
As More Senate Democrats Support Blocking Gorsuch, Remember When Reid And Schumer Said This About Filibusters