Place a commodity box next to where you store your fish. deed up what you need , take to the boat, drop deeds in hold, undeed them , drop in the crates as needed,
They weigh nearly nothing and can be transported easily.
While it is a possible solution, I see it more as a convoluted work around rather then a "real" solution...
It needs a whole lot of commodity deeds and, considering that a crate can be with 6 lines and there is many crates to fill up and deliver, soon the commodity deeds would become tens upon tens if not hundreds to have to stock up...
I'd rather prefer a fish/crabs/lobsters weight reduction Satchel where one can just put in all of the fish, crabs and lobsters needed to fill up 1 Quest crate, recall away to fill up the Quest Crate and end of the story, no need to have to keep stocking up tons of commodity deeds....
Besides, it also serves another scope.... the Developers, in order to keep players interested in playing the game, need to always come up with new items, new Rewards that might be of interest to players so as to keep players hooked onto playing the game....
Well, such a fish/crabs/lobsters Weight reduction Satchel would be a step towards that direction, a new item to keep players interested in playing the game as it would be an item that could help them usefully...
Of course, since Commodity deeds are blessed, in order for such a Satchel to be able to compete and be "more" usefull as the use of Commodity deeds you suggest, it would need to come as Blessed, in any and all rulesets, otherwise, players would find no convenience in using it (if they get killed in PvP ruleset areas they would still get to keep their blessed and filled commodity deeds but not an unblessed fish/crabs/lobsters Weight reduction Satchel thus risking to loose their hard earned fish, crabs and lobsters...) and would simply use the Commodity deeds instead.
There is no point in working men hours to Develop items which then players would not use when they have better alternatives, already in the game, me thinks.
Either the new items are an "improvement" over what players currently have and can use in the game, or they would just be a waste of Developers' time since players would not use them and use whatever works better that they can currently use.
That is at least how I see it.