GTC, Good 'til Cancelled. What are the downsides?

[vidim]

So I have many products whose supply is limitless. IE they never get sold out. I just have them on repeat listing. 30 days.

There is an upsell (within Ebay) from within these listings. But I need to make the upsell a permanent, GTC, link, since I do not want to go in and edit inside the linking listing and make a valid link every time.

I am just assuming that upsells to a relevant product within Ebay is perfectly allowed.

So what are the downsides of GTC? I understand that they might become semi-ghosted unless they actually sell. Anything else?

Any other good ways of getting a permanent link to a listing if I choose NOT to do GTC? I suppose I could just link to the: product name or SKU + only show listings from my username. Any downsides with this method, apart from the link leading to a search results page, and not to the actual listing?

Thanks all