Is it obligatory to delay the Asr prayer to perform it in congregation at a Hanafi mosque that delays it until close to Maghrib, or should it be prayed individually at the beginning of its time at the workplace due to the unavailability of a nearby Salafi mosque?

The optional time for the Asr prayer begins from the end of the Dhuhr time until the sun turns yellow, and it is not permissible to delay it beyond that except out of necessity. There is no harm in delaying the Asr prayer as long as the sun has not turned yellow, but it is preferable to perform it earlier without missing the congregational prayer. The Deobandis adopt the Maturidi school of thought in creed, and some of them belong to Sufi orders. Prayer behind an innovator (Mubtadi') is valid as long as their innovation is not one of disbelief (Kufr). A Muslim should seek an Imam who is not an innovator if possible. If the Imam of the mosque is not known to commit acts of polytheism (Shirk), then praying behind him is valid, even if he delays Asr, and it is not permissible to miss the congregation for that reason.