First of all, a transferable SBLC is uncommon. Usually, people use transferable DLC. This is because the SBLC is a payment guarantee, a security and not a payment instrument. A DLC is a payment instrument, in which payment will only be effected against a complying presentation.
As a applicant, you have no idea your beneficiary (first beneficiary) is going to transfer the SBLC to who since the purpose of being transferable is to allow the middle-person (the first beneficiary) to be able to provide a security to the supplier(s) (secondary beneficiary) without having to go to a bank to issue a LC which involve additional time and money. Issuing a SBLC require the applicant to maintain a current account of sufficient fund or other form of collateral ranging from cash, fixed assets like factories or machinery, company stock to negotiable bill of lading consigned or endorsed to the order of the bank. All your counterparty need to do is pay a transferring fee to have the LC received from you transferred to his/her supplier.
Potential problem for you as applicant:
1) You don't know the profile of the 2nd beneficiary which your counterparty (first beneficiary) is going to transfer your SBLC to. There can be one or more 2nd beneficiaries. You are essentially taking on the risk of not just your counterparty but also that of the 2nd beneficiary or beneficiaries. The risk is that of claim on the SBLC by either your counterparty (first beneficiary) or 2nd beneficiary/beneficiaries.
2) Of course, the more 2nd beneficiaries, the higher risk for you as the applicant. If one 2nd beneficiary decide to make a claim on the SBLC, the claim will be in full as there will not be partial claim.
3) Under a SBLC arrangement, you the applicant are required to effect payment on maturity date directly to your counterparty. There can a case where you have to pay double the amount. You effected payment to your counterparty on maturity date. Then unknown to you, the 2nd beneficiary or beneficiaries decided to make a claim on the transferred SBLC. Your issuing bank will have to honor the claim upon first demand. The 2nd beneficiary or beneficiaries don't have to evidence that an actual event of non-payment exist.
4) If things goes bad, you will not get the ordered cargo and there is no way around it except to sue the seller for breach of sales contract. A SBLC only benefits the seller, not the buyer.
By issuing a transferable SBLC, you actually guarantee to effect payment not only to your immediate counterparty (first beneficiary) but also to the 2nd beneficiary. A guarantee to effect payment via the form of SBLC should be available to the party with whom your company signed contract with.
The only way to stop your issuing bank from paying out in an unfair situation like point (3) above is to go to a local law court (if SBLC is issued subjected to your country law) and file for a court motion. However, in most cases, a court motion will only be issued out against very compelling reasons.