The sellers supplying goods through e-Commerce operators (ECO) may have common places of business, especially if their goods are stored in a shared facility operated by the ECO. This will result in the same additional place of business being registered by multiple suppliers. Is this allowed

Yes, this is allowed. Any registered person can declare a premises as a place of business if he has requisite documents for use of the premises as his place of business (like ownership document, agreement with the owner etc.) and there is no restriction about use of a premises by multiple persons. The registered person shall have to comply with the requirements of maintaining records as per section 35 of the CGST Act, 2017 and Rules 56 to 58 of the CGST Rules, 2017.

(FAQ 18: E-COMMERCE)