Preventing Pages theme from being imposed on each aspx page directive during compilation

Preventing Pages theme from being imposed on each aspx page directive
during compilation

in my web.config i use the following pages declaration
<pages maintainScrollPositionOnPostBack="true" Theme="Theme1">
with the intention of being able to use different themes on a web
application to customize the way it displays for a few different
clients(some of which want their own branding on the web application's
pages)
if i leave out the theme directive in my development code, it doesn't
display properly when debugging, so i want to have the Theme defined in
the web.config... however when it is defined as above and i go to publish
my solution every .aspx page declaration goes from this:
<%@ Page Language="VB" CodeFile="MRSHome.aspx.vb"%>
to this:
<%@ page language="VB" inherits="App_Web_peiwi24o" theme="Theme1"
maintainScrollPositionOnPostBack="true" %>
and page level theme declarations override the ones set in the web.config
file, i need that to remain the case since some pages programmatically
switch to a print friendly theme when the user needs it.
How do i prevent the web.configs pages settings from being appended to
each page's page declaration during compilation?