Is it permissible for a traveler to a place where ignorant people and innovators are abundant to make adjustments to his actions and words to avoid discord and focus on essential matters, such as speaking about Tawhid instead of justifying some Sunnahs?

If performing the supererogatory acts (Sunan) established from the Prophet, peace and blessings be upon him, would lead to confusion, discord (fitna), or alienating people from the caller (da'i), then there is no harm in omitting them, out of consideration for the situation and to avert harm. This is especially true since engaging in teaching Tawhid (monotheism) and Aqidah (creed) is more important. Allah knows the intention and will reward for it.