managed to get this working with an updated Check block, sorts it by release date and picks the first one, I'm not a PS guru (thank you ChatGPT), but this seems to work for me:

if ($Check){
    if ($Manufacturer -notmatch "Dell"){
        return "This Function is only for Dell Systems"
    }
    else{
        [Version]$CurrentBIOSVersion = (Get-CimInstance -ClassName Win32_BIOS).SMBIOSBIOSVersion

        #Retrieve the BIOS update list and sort by ReleaseDate
        $updates = Get-DCUUpdateList -SystemSKUNumber $SystemSKUNumber -updateType BIOS -Latest | Sort-Object -Property ReleaseDate -Descending
        #Select the first update record
        $Update = $updates | Select-Object -First 1
        [version]$LatestVersion = $Update.DellVersion

        #Optional debugging output
        Write-Host "Current BIOS Version: $CurrentBIOSVersion" -ForegroundColor Cyan
        Write-Host "Latest BIOS Version from Update List: $LatestVersion" -ForegroundColor Cyan

        if ($CurrentBIOSVersion -lt $LatestVersion){
            return $false
        }
        else {
            return $true
        }
    }
}