So my friend's server modpack updated and the old accumulators I already crafted are still there somehow, but frankly, I found a new use for them!

They make for fantastic portable batteries since they don't lose charge when you mine them. My suggestion is to keep the old accumulator and its recipe but rework it as "Portable battery" or something along the lines of that. I'm fine with the old and awkward recipe for it (Could even be something new) since portable FE is potentially really powerful. I'm also fine with them not stacking.

For example, it can be used to power a portable system requiring a hose pulley , an electrical motor, a pump, a block detector, some redstone, a few cogs and a piston to drain large bodies of water far away from other energy sources. Basically giving you a limited amount of FE (up to 4.2 Mfe) to power any machine which can support the stress capacity of an electrical motor at max speed anywhere you want

I hope you will consider my suggestion. Thank you!

The old accumulator is still there (i saw it with my own eyes too).
It is a great idea to keep it!