GSP screening-out of prohibited and/or restricted items at the macro level happens at the eBay listing category, and probably after that comes bots which read the various data entered into your listing and do further screening. They probably have bots that search your written description for keywords.
Items that are OK for one country but not another will of course have the item shown to eBay members based in the allowing country and not shown to eBay members in countries where that particular item is not allowed.
I have to think that the GSP restrictions would be set to "too tight" rather than "too loose" in order to minimize situatons where the GSP gets stuck with an item it can't deliver due to restrictions---every one of those non-deliverables would cost money due to refunding shipping costs, their service fee, and going thru the hassle of disposing of property.
Based on my own experience on another account selling an automotive machinists product, first check the USPS site https://pe.usps.com/text/imm/ab_toc.htm for detailed specifics about what is and is not permitted to be sent to your target county (Maldives), and compare that with the exact item you are sending. If you conclude that your item should be OK to send, yet the GSP screening is keeping it out of Maldives, then try juggling the category to others where your item would reasonably fit. I found that my particular item was not OK to GSP-ship to Great Britain when listed as a metal working/machine tool, but was OK to GSP-ship when listed as an automotive repair tool. It's routine to find that particular item listed in either category and some Sellers cross-list them in both categories.
