Weighted calf raise exercise and how holding weights might affect them.

I was requested by my Physio a few days ago to include calf raises in an attempt to resolve a few issues I am having down there. (lack of flexibility in some areas, hypermobility in others, instability in cushioning etc)
The exercise itself is fine and I am able to do it as requested with the exception of one point. He mentioned that I should be aiming to use a weight that is suitable for 8-10 reps and 6+ sets throughout the day. However from home, I only have access to at most 10kg plates in each hand. I was told to use dumbells or a similar object for this exercise.
10kg in each hand plus my own weight of 104kg is not sufficient weight to force me to stop at the 8-10 rep range and I can easily shoot into the 20's with no strain whatsoever. I am ensuring that I lock my knees when I am doing these so i know that I'm not merely taking the strain onto larger muscles as the only body parts that move during the process is my ankles and my hips (if i bend to maintain balance)

With this backstory out of the way, my question is. Can I increase the weight by holding onto a bar with plates added rather than holding a single object in each hand. If I have access to this option I could easily increase the total weight by another 40 or so kg which might prove to be sufficient. I am unsure if this would change the motion or the point of the movement so I thought to find an online forum and ask first.

Cheers in advance.