What is an overview of arguments given by churches that allow women to plait their hair to support that practice? (1 Peter 3:1-6) Consider this passage from 1 Peter 3,

1 Peter 3:1-6 KJV Likewise, ye wives, be in subjection to your own husbands; that, if any obey not the word, they also may without the word be won by the conversation of the wives;
While they behold your chaste conversation coupled with fear.
Whose adorning let it not be that outward adorning of plaiting the hair, and of wearing of gold, or of putting on of apparel;
But let it be the hidden man of the heart, in that which is not corruptible, even the ornament of a meek and quiet spirit, which is in the sight of God of great price.
For after this manner in the old time the holy women also, who trusted in God, adorned themselves, being in subjection unto their own husbands:
Even as Sara obeyed Abraham, calling him lord: whose daughters ye are, as long as ye do well, and are not afraid with any amazement.

Assuming that the Bible is the authoritative word of God, what is an overview of arguments that are given by pastors or congregations who allow female attendees to wear their hair in plaits?
3:1 Wives, in the same way submit yourselves to your own husbands so that, if any of them do not believe the word, they may be won over without words by the behavior of their wives,

This is one of the most misunderstood lines in the Bible, which in its first glance is a clear expression of misogyny. It isn't. This is to actually teach the women to be creative in their ways to pitch to their husbands the beauty of Jesus' word. Society during Biblical times are truthfully, so limiting to women that any overt attempt for women to Christianize their husband would be seen as emasculating. The women, thus, need to be subtle.

2 when they see the purity and reverence of your lives.

Simply, actions speak louder than words. A naggy woman preaching the Word of God is more off-putting than a quiet woman showing a Christian lifestyle, don't you think?

3 Your beauty should not come from outward adornment, such as elaborate hairstyles and the wearing of gold jewelry or fine clothes.

This is actually feministic, as it says that women, who tend to be insecure about their looks more than men, have to stop validating their appeal from society's unrealistic expectations of beauty, especially men's sexual desires.

4 Rather, it should be that of your inner self, the unfading beauty of a gentle and quiet spirit, which is of great worth in God’s sight.

Again, subtlety and integrity of character as a measure of beauty.

5 For this is the way the holy women of the past who put their hope in God used to adorn themselves. They submitted themselves to their own husbands,
6 like Sarah, who obeyed Abraham and called him her lord. You are her daughters if you do what is right and do not give way to fear.

That again, being lower than a man in the food chain may be an oppressive condition, but it can be used as leverage, especially in showing that the Christian way of life is superior to any other lifestyle.
A smart eagle does not show her claws.