I have been splicing eyes in my throwline for well over 10 years. I do a long bury splice with a taper, about 12”-15” (30 to 38cm)
I have found that the double amount of Throwline, because of the bury, increases the longevity of my lines. Makes attaching lines, extra weight simple. It also makes friction management device retrieval smother.
I have never had any issues with lines getting stuck due to the splices specifically. I would say just the opposite, but I cannot quantify it.
I have also end to end spliced cut or damaged Throwline with good results.
I did a video on it a few months ago for Arboriculture Canada on my process. Not sure if it was posted yet…
Tony