I should say right up front that I have specific examples from my own personal experience in mind as I write this, but the truth of what I say isn't dependent on that.
I've outlined what I object to in the doctrine of penal substitution, viz:
the doctrine is believed in wholeheartedly and the consequence drawn from the doctrine, within the life of the believer, is that the character of God is fundamentally one of inexorable justice; that the response to any transgression is 'there must be punishment'; and that the life and witness of Jesus Christ is conformed to this controlling narrative, rather than all other narratives being conformed to the life and witness of Christ.
In other words - there is a distortion in belief, in terms of the prominence given to punishment when describing God's character (a form of idolatry), and there is a distortion in christian behaviour consequent to this, which (to summarise in advance) becomes a form of 'law not grace' - guilt is prominent, and fostered, and forgiveness is underemphasised. Where rules and punishment are given excessive emphasis in the presentation of salvation there will be consequent harm done to the listeners. Where there is paradox - God is a God of justice and mercy/forgiveness - then much depends on how things are presented, if one isn't to eclipse the other.
I'll unpack that, as it's quite dense, and begs lots of questions.
1. The character of God
Advocacy of this form of PSA would emphasise the holiness of God, understood as the utter incompatibility of sin with God's existence. Such sin would be seen in personal and individualistic terms, and much would be made of the offence given to God. There would be less emphasis upon the gracious and forgiving aspects of God's character, along with the corporate side of sin.
2. The character of Scriptural witness
PSA would be seen as either the sole or the determining way in which Scripture talks about redemption. Texts referring to PSA would be given the highest possible prominence; texts which give different models would be addressed less; arguments about the character of Scripture as a whole would be downplayed. The teaching of Jesus, eg about the Kingdom, would be considered much less important than the achievement of the crucifixion - understood through the lens of PSA.
3. The nature of preaching and the call to repentance
Emphasis would be given to the way in which humanity has sinned and broken the laws of God; PSA would be explained and the guilt provoked would, instead of being eliminated, be nourished as a healthy response to 'the truth'. The important thing for a disciple would be to understand the way in which 'Christ died for you'.
4. The nature of church behaviour
Consequent to the consistent emphasis upon rules and the breaking of rules, there would be an excessive concern to establish and police the boundaries between the rule keepers and the rule breakers, in order to prevent further provocation of God.
5. The tone of advocacy
There will be a shrillness of tone (eg "damn this diabolical doctrine to hell" ;-) associated with discussions on the topic; this will be directly linked to the level of fear of punishment felt by the advocate. There will be little concern to understand the objections to PSA, and there will be a comprehensive rejection of the possibility of Christianity without an acceptance of PSA.
6. The most important: the pastoral character of doctrine
The sheep pastored under this understanding of PSA will remain bound up in guilt and sin; they will not be enabled to experience forgiveness; they will remain emotionally crippled and not enjoy the abundance of life promised. Aware of their own sinfulness they will be reminded of it on regular occasions and not encouraged to affirm their original blessing of being made in the image of God.
Now - obviously! - these are very broad brush strokes, but I think they will serve for the time being. The question is: do such places and advocates exist? That's for the next part.