I've heard a number of people suggest that you should soak a new spool of line in hot water just prior to spooling up in an effort to make it more supple. My question is: is it ok to do this multiple times to larger spools of line? I just got a 1 lb spool of Yo Zuri and want to do this (as well as a slathering of KVD), but I don't know if multiple hot water dunks will break down the line over time. If not Yo-Zuri because it is a hybrid, what about pure fluoro? Yes, yes, before you say " why would you ask such a question? you throw your line in water repeatedly". That is true, but I don't fish in hot water springs. Who knows if the repeated heating and cooling will cause long term damage.

I don't think any damage will be done to the line on repeated soakings, the water does not have to be all that hot.  

You won't do any damage. IMHO the only advantage I can see is the line is a bit softer when you put it on but right back to the original stiffness when it cools. Mono absorbs a little water but I doubt that any extra is retained from trip to trip. I do know of nylon auto parts molded in Indiana and shipped to El Paso had breakage problems do to the dry conditions. The reason to soak in hot water is temperature control. You can't get the water over 212F. While hot soaking can be helpfut for some putting mono on your reel correctly eliminates the need for soaking.

1st I don't think multipule donking in hot/warm water will matter.   My solution is to donk the line after spooling it to reset it to the reel.  Basicly the same thing.  Warm line spools easily and don't jump off the spool like cold line.