I use 5L beakers, then 3,2,1 etc. But largest is 5L. I stumbled on few of those few years ago. Old SIMAX brand, quite thick glass. Max I am willing to put in is 4 liters. Then it is very unstable in gloved hands, espetially sweaty.
I like to grab the beaker by the upper edge with one hand and help with other hand from the bottom to pour the contents etc. That is my limit. If I cannot grab it on the upper edge with my fingers inside the beaker (not submerged), then I do not fill more. One has to think that one liter of saturated copper AP or AR is more than one kg. So you are lifting not 4kg but more than 5-6 kg for example. That is considerable weight and not all unbranded thin wall beakers could withstand this.
I had cracked beakers only from accidents with bad handling, denting the bottom of the beaker with stirring rod or it just slipped in wet gloved hands, denting the bottom and making expensive mess
More than 4-5 liters and I am making the thing in few parallel 5l beakers. More than 10L and it gets interesting
How to heat the solution in plastic canister
then it become considerably more difficult in the terms of handling and espetially heating. There are several tricks for this, but I mainly have duplicator or heating glass spiral for this. Insulation is very important... Etc. Whole another world
When you leave safe world of beakers
then, I would consider purchasing some durable peristaltic pump with BPT tube to withstand the corrosive liquids. Safe, easy, and convenient. It is also good for continous filtration systems (barrel to barrel).