According to what I have red, no. They mate long term and defend each other, if one of them dies it is hard or impossible to make the other angel accept a new mating partner.
I have bred Angels for years, and they do not mate for too long. If I removed one of the pair, the other will soon fine another mate. I did this for a while to choose better color fry.
In the wild, they mate for a single breeding period. In an aquarium, mating for longer than that isn't a breeding strategy, but mostly a lack of options.
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