Intercompany sales during SAP Hana S/4 migration

Dear Experts,

Our institution is successful the midst of migration to SAP Hana S/4 from ECC 6.0

We are operating successful each European countries and  the migration is planned successful phases/waves. Current script we person aggregate institution codes and plants successful each EU locations moving connected a azygous lawsuit of ECC 6

so my question is if we are selling from accidental Belgium with the delivering works successful France( existent scenario) and successful the archetypal signifier lone Belgium CoCode volition beryllium migrated to S/4, however bash we manages income with the delivering works being successful France( connected aged ECC system) not being disposable to Belgium Sales Area ( connected the caller S/4 system)?

This is lone 1 script and the reverse concern volition besides hap with income from France Sales org( connected ECC) being delivered from Belgium works ( connected S/4) 

So we volition person 2 strategy moving successful parallel during transition, with nary banal visibility betwixt each other, however tin this beryllium managed ? 

Please if anyone has been successful this concern tin stock however it was managed ?

Thank you for your responses

Kind Regards

Apoorva