So let me put this very simply and bluntly so we can all think about it carefully...
...what is a DBS for? Who is it designed to stop? And where does the system fail?
It's supposed to stop anyone who is a threat and intends to break the law and is a threat to children.
Therefore the people there is a problem with are the people who will commit fraud if it gives them opportunities to carry out illegal activities.
Why are people who claim a trans identity and issue in this context?
Changing name itself is a potential issue. It makes it more difficult to track someone even with other name disclosures.
The people who are most likely to change their name are women. The vast majority of name changes are by marriage. This is where you note patterns of offending - women are significantly less likely to have been involved in any kind of violent crime and even less likely to be involved in a sexual based crime. So risk here is lower. Men are significantly less likely to change their name.
Then you start to look at other reasons to change name and it does start to get murkier. There's having a name you don't like, family complications, being trans and because you have something to hide.
You have to take the last group very seriously. This group are very willing to lie, and will have good reason to. They don't mind a bit of fraud. They are criminals and their intent is to commit criminal activity. Now this group can include women, but sex based patterns of offending reveal that women are still low risk.
Now let's take this further in terms of understanding criminal patterns. Sex offenders are overwhelming male and unfortunately figures show that trans identifying males are over represented in this group. We should be taking applications for name changes in this group, more seriously and reducing the ability to defraud most within this group.
Instead their loopholes that make it harder to verify identity, and one of the risks here is over reliance on the DBS itself and not checking information relating to identity elsewhere. The loopholes make that harder. Plus you need to factor in that makes who change their name are effectively higher risk than males who don't, and females who do to begin with.
Sexual abuser by nature look for weaknesses in systems to make it easier to escape detection.
The point about fraud and trans people telling the truth is irrelevant. The issue is the loophole and the liar. And who is higher risk of doing that, and why.
The risk is ALWAYS about people who WANT to lie and deceive. It's not about the innocent nice transwoman who is your friend and wouldn't hurt a fly and therefore criticising the system is 'transphobic'. No the system has weaknesses and unfortunately the profile for a trans identifying males is much higher than the general population therefore the checks need to be, at least equal to, if not higher for this group if we take safeguarding and prevention of fraud seriously. Instead we have the opposite dynamic where checks are actually weaker than anywhere else.
Risk assessing is about seeing behaviour patterns not identity. In law we can't discriminate in a way that disproportionately affects one group, but we certainly could tighten checks that are weaker for one group if we can demonstrate everyone is being treated equally for legitimate concerns about criminal behaviour. In other words we close the loophole and talk about how the loophole attracts people with criminal intent, who may claim trans identity nefariously in order to help their offending.
Laws are there not to prevent law abiding citizens from offending. Laws are there because criminals offend and lie and cheat. The DBS is trying to detect criminals. If fraudly filling in a DBS is too easy under certain circumstances then we need to look at this.
In other words when we look at criminal behaviour we aren't remotely interested in the behaviour of 'the nice transperson'. We are interested in the patterns of behaviour of criminals and how criminals can exploit. One of these happens to be through exploiting the good nature of people who think we all should be kind and not talk about offending patterns because they think it's 'transphobic'. It makes us blind to the people who are a problem if we focus on the good people.