regardless of属于复合介词，而介词of后是可以接名词性从句的，当然也有说regardless of whether可以看作是复合从属连词，但这样就无法解释regardless of what…了。
是故，还是把regardless of视为如同“because of”类的复合介词更为妥帖。
《麦克米伦高阶英汉双解词典》第1741页regardless词条
regardless of不顾；不管
We will continue the race, regardless of the weather.
不管天气如何，我们将继续比赛。
There must be equality of rights for all citizens, regardless of nationality.
不分民族，所有公民权利均等。
regardless of how/what/why etc
The building work will proceed regardless of whether?there is an agreement.
不管是否有协议，建筑工程将继续下去。
《剑桥美国英语词典》第1059页regardless词条
regardless无论如何；不管怎样
We want tax cuts, but regardless, we need to limit expenditures.
减税我们当然想，但无论如何我们必须限制开支。
I tell the truth,?regardless of (= without attention to) whatthey want to hear.
不管他们想听什么，我都得讲实话。
《当代美国英语学习词典》第1276页regardless词条
regardless不顾；不论
Regardless of what?his parents think, he is going to leave home.
不管父母怎么想，他打算离开家。
《柯林斯高阶英汉双解学习词典》第2201页regardless词条
regardless of不顾；不管；不论
Regardless of whether?he is right or wrong, we have to abide by his decisions.
不管他正确与否，我们都得服从他的决定。
《牛津高阶英汉双解词典》第八版第1727页regardless词条
regardless of不管；不顾；不理会
The amount will be paid to everyoneregardless of whether?they have children or not.
不管有没有孩子，每个人都会得到相同的金额。