Pérez certainly seems better than the openly neoliberal candidate Lasso, who appears to have lost the first round; however, it's important to remember that he had actually supported Guillermo Lasso's candidacy in the 2017 presidential elections. Lasso has also reportedly said he’d support Pérez in the 2nd round. There unfortunately are a plethora of red flags with Yaku Pérez:

Ecuadorian indigenous leader, Leonidas Iza, reports that there are right-wing elements from bankers candidate Guillermo Lasso, in Yaku Pérez's inner circle, directing policy. Iza is from Pérez's party, he's concerned about the elite interests within it.

Leonidas Iza is from the national leadership of @CONAIE_Ecuador, he was a key leader of the October 2019 uprsing against the IMF. He represents the grassroots of the party.

There seems to be a serious disconnect between Pérez and CONAIE with its rank and file.

Yaku Pérez has a lot of comments that raise doubt about his purported leftist credentials:

When asked about Andrés Arauz's plan to give $1,000 to 1 million mothers who are the heads of their households once he's elected president, Yaku Pérez claimed these people will "probably spend it all on beer that same day."

According to Leonidas Iza, an indigenous leader and president of the Indigenous and Peasant Movement of Cotopaxi, Evo Morales did not invite Yaku Pérez to the inauguration because the Pachakutik candidate celebrated the right-wing dictatorship in Bolivia. Pérez also never condemned the Anez regime's massacre against indigenous protestors. He has instead accused Morales and Correa of “authoritarianism, machismo, extractivism, and populism.” Evo has backed Aruaz. Yaku rooted for the socialist Maduro and Correa governments to "fall":

“Now all that’s missing is for Rafael Correa and Maduro to fall. It is just a matter of time.”