In every election where re-electing the president is prohibited, changing the constitution to allow the current president to run again has been a feature.
Leonel only allowed one term in the late 1990's by changing that aspect of the constitution. That is why Danilo ran for president representing the PLD in the 2000 election and lost to Hipolito representing the PRD. Leonel basically shot himself in the foot because he would had won that election. His first term was considered good at the time. Hipolito change the constitution to allow the president in office to run for the presidency in the 2004 election. He lost to Leonel (PLD) and left that aspect alone. In 2008 Leonel won again because Hipolito changed the constitution to allow 2 consecutive terms if a president is re-elected. In 2012 Danilo (PLD) won because Leonel wasn't allowed to run again for that presidency, per the constitution. Danilo won again in the 2016 election. Now Danilo hit a road block because that aspect of the constitution says he can't run again, albeit he can run in the 2024 election.
Before, when Balaguer was president, the constitution never put any limit on how many times a sitting president can run for re-election. That is why he was the president so many times and at such an old age. The Americans forced him to end early his last presidency, cutting that one in half. He and Juan Bosch (at that time he already suffered from dementia and people that accompany him say he was not himself or thinking right) made sure that Leonel won and in the 1996 election Leonel won his first election.
I don't think he is going to change that aspect of the constitution. At this point he is simply Danilo being Danilo. I don't know why Leonel didn't left that aspect of the constitution alone and allow a sitting president to be re-elected until he dies. That's basically what some wants.