That sort of thing has been going on for years , our lake has had ,
Goldfish ,they dont last think the pike love them , Bull Frog ,noisey creature ,Terrapins , Koi Carp , their just the ones that come to mind.
Ive often wondered this ,if it does it must be really negligible given how carp rods are used in general .
I guess you could test the rod , now as I understand it ,if your rod is 3 lb TC then attach a 3lb weight to your line and lift , your rod should be horizontal and your tip vertical pointing to the ground as you lift.
I do stand to be corrected on this ,but thats how I understand it
Packed up and home now a couple of hours , rain eased when packing up but still everything is wet ,π° the Army DPM, Gortex equivalent is absolutely 100% waterproof
Final tally came to 4 Carp landed an 2 lost
Not sure where you are but their are plenty of double figure Smooth hounds down here on the South coast beaches < some are better than others.
If you didnt know already this is a very good Forum .
https://www.worldseafishing.com/forums/
If your someone who has to have their Bivvy all shut up when you go to sleep or a tiny letter box gap then a Bivvy heater is just asking for trouble ,
I had one bought for me last year ,but as I never have the front on my Brolly or Titan its never going to be a problem , and if the front does go on its because im facing into the rain and that in its self means its warmer so no need for one .
So it all comes down to whether or not you have the intelligence to use one correctly , IMO they are not dangerous , The danger is in the way they are used.