XAdES validation extremely slow using old transformation/canonicalization algorithm

When the old transformation algorithm

<ds:Transform Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116">
   <ds:XPath>not(ancestor-or-self::ds:Signature)</ds:XPath>
</ds:Transform>

is used in a XAdES signature the validation of the signature takes "forever" (3.59MB XML file, about 3 hours).

Using the more modern XPath2Filter 

<ds:Transform Algorithm="http://www.w3.org/2002/06/xmldsig-filter2"> 
   <dsig-xpath:XPath Filter="subtract" xmlns:dsig-xpath="http://www.w3.org/2002/06/xmldsig-filter2">/descendant::ds:Signature</dsig-xpath:XPath>
</ds:Transform> 

there's no such issue.

The call which causes this issue is org.apache.xml.security.signature.XMLSignature#checkSignatureValue(java.security.cert.X509Certificate)

Unfortunately I don't have any control on the signatures I receive.

Do you plan to optimize it? Is there a workaround?

I'm sorry but I can't attach the file I used, but you can find similar samples here where the same issue is raised.