How to compare integer in Precondition for B2C Custom Policy? Also how to Convert int to string?

Question

Strap in, because this one is a doozy.

Problem Statement: I want to read user id from our SQL DB, and store it as a custom attribute in B2C. If it exists in B2C, read from custom attribute and never hit SQL DB.

I am looking for a way to compare an custom attribute integer claim using the ClaimEquals Precondition. ClaimEquals only works for strings or booleans, so in order to use this type, I first need to turn my integer claim into a string. Although, the only ClaimsTransformation offered for number -> string is ConvertNumberToStringClaim which only supports long -> string. Although, on B2C, long isn't even offered as a type for custom attributes. So what I tried to do is I defined my custom attribute as an int, and just define the extension_userId in the custom policy as a long. Although, this initially worked, after attempting to re-upload the custom policies, it throws a syntax error on the final step telling me that when I am forced to default the value, that 0 is a type mis-match with long. So in order to get this to work, I have to revert certain key changes, upload the policies out of order, and then re-upload the extensions policy. This technically works but is the worst thing I've ever done in programming.

So my question is,

How do you compare an integer in a Precondition using Custom Policies? and How do you convert an int to a string?

Thanks

Relevant Code:

   <ClaimType Id="Id">  
     <DisplayName>Id</DisplayName>  
     <DataType>long</DataType> <!-- Actually an integer -->  
     <AdminHelpText>extension_Id</AdminHelpText>  
     <UserHelpText>extension_Id</UserHelpText>  
   </ClaimType>  
     
   <ClaimType Id="extension_Id">  
     <DisplayName>extension_Id</DisplayName>  
     <DataType>long</DataType> <!-- Actually an integer -->  
     <AdminHelpText>extension_Id</AdminHelpText>  
     <UserHelpText>extension_Id</UserHelpText>  
   </ClaimType>  
     
   <ClaimsTransformation Id="CopyId_string" TransformationMethod="ConvertNumberToStringClaim">  
   				<InputClaims>  
   					<InputClaim ClaimTypeReferenceId="Id" TransformationClaimType="inputClaim"/>  
   				</InputClaims>  
   				<OutputClaims>  
   					<OutputClaim ClaimTypeReferenceId="Id_string" TransformationClaimType="outputClaim"/>  
   				</OutputClaims>  
   </ClaimsTransformation>  
     
   <!-- If custom attribute doesn't exist, read from API -->  
   <OrchestrationStep Order ="5" Type="InvokeSubJourney">  
   					<Preconditions>  
   						<!-- If Id > 0, skip this orchestration step-->  
   						<Precondition Type="ClaimEquals" ExecuteActionsIf="false">  
   							<Value>MMId_string</Value>  
   							<Value>0</Value>  
   							<Action>SkipThisOrchestrationStep</Action>  
   						</Precondition>  
   					</Preconditions>  
   					<JourneyList>  
   						<Candidate SubJourneyReferenceId="read-from-api"/>  
   					</JourneyList>  
   </OrchestrationStep>  

PS: I would just use ClaimsExist, but am forced to default the value because there is no null checking.