Politico reported on January 19, 2017, that the incoming Trump administration named Szubin among officials asked to stay, and that incoming press secretary Sean Spicer told reporters the president-elect would keep him on to keep posts filled. A companion Politico item listed Szubin with other holdovers (Rasmussen, McGurk, Shannon) as remaining after inauguration.
That is reporting of a transition statement. It is not a primary White House transcript located for this draft. It is not evidence that Szubin campaigned for Trump, endorsed Trump, or was a political ally. The same week, a Treasury spokesperson said he would serve as Acting Secretary until a new secretary was confirmed and then leave government. Continuity is not the same thing as documented Trump-friendly service. This site does not invent friendliness.
Jewish Telegraphic Agency summarized the same ask and noted Szubin had called the Iran deal a tremendous diplomatic breakthrough — language that matches his April 13, 2016, Treasury remarks. JTA is reporting.