Is it recommendable or an innovation to persist in reciting weak hadiths found in morning and evening supplications, repeating them a specific number of times?

There is no harm in persistently reciting the morning and evening adhkar (remembrances) that are mentioned in weak hadiths, as it is permissible to act upon a weak hadith in matters of virtues of deeds, provided it is not severely weak and falls under an original principle. However, if the hadiths are severely weak, then persistently repeating the dhikr with the number mentioned therein is considered an additional innovation (bid‘ah).