To mitigate potential compliance risks, the LLP should ensure proper documentation, including a tax invoice for the sale from the Ltd Co to the LLP and a delivery challan for the movement to the port under Rule 55 of the CGST Rules. Although an E-Way Bill (EWB) is not required for intra-building transfers, it is advisable to generate one when goods move to the port to avoid disputes. Additionally, maintaining clear records of stock movement, GST filings, and export documentation will help justify the transaction's legitimacy in case of scrutiny. Seeking an Advance Ruling on the applicability of EWB in such cases can also provide legal certainty. If you still have questions, reach out to me and I'll help you further.