unable to set additional jdbc parameters in datasource

Hi,
I am working on a development configuration of a TomEE 8.4, trying to add additional jdbc parameters to a (working) datasource.
Here's the datasource:

<Resource id="jdbc/mydatasource" type="DataSource">
JdbcDriver org.postgresql.Driver
JdbcUrl jdbc:postgresql://database:5432/postgres
UserName myusername
Password mypassword
</Resource>

In my application I need to call stored procedures using JPA: it seems that, in order to use 'call' rather than 'select', I have to add additional parameter to the jdbc driver (https://jdbc.postgresql.org/documentation/callproc/), namely escapeSyntaxCallMode.
Now, since I want to have a default schema (other than public) set, I also have to set the parameter currentSchema=myschema.
If I were to create a jdbc url string I would concatenate both at the end of the current url as JdbcUrl jdbc:postgresql://database:5432/postgres?currentSchema=myschema&escapeSyntaxCallMode=call
Unfortunately this generates a sax exception.
Checking both TomEE and Tomcat documentation I have found that I am supposed to pass additional params using the connectionProperties property (https://tomee.apache.org/datasource-config.html#connectionProperties). Unfortunately the props don't seem to be passed to the jdbc driver because I am getting errors such as

05/10/2023 6:00:19 PM
2023-05-10 16:00:19.005 UTC [53] ERROR: p_mui_update_esito_pubblicaz() is a procedure at character 15
05/10/2023 6:00:19 PM
2023-05-10 16:00:19.005 UTC [53] HINT: To call a procedure, use CALL.

Here's my questions :
How do I check how TomEE opens a connetion to the database (is there any logging I can set in order to inspect that? )

Has anyone had issues with (extra) connection properties ?

Before you ask: I have the correct jdbc driver (the one that supports the named param: postgresql-42.6.0.jar) and postgres server (14.7)
Any help would greatly be appreciated
Regards,
Marco F.