The fix for DC crud: linear power supplies. Now, with the Intellijel cabs, you've got to deal with the internal switching supply, and there's not a lot you can do there. BUT...you might consider replacing the Meanwell "brick", which is ALSO a switching supply. Reason is, if you've already got crud coming into the cab from that brick, this can then screw majorly with the noise factor of the Intellijel TPS unit in the case.
With my AE system, I use a Tektronix PS281, but this is probably a bit underpowered for the Intellijel's needs. Instead, the next model up (the PS282, as shown here: g~gAAOSwTOxfoFD0" target="_blank">https://www.ebay.com/itm/Tektronix-PS282-DC-Power-Supply-5A-18V-TW10205/402528809979?epid=1117948359&hash=item5db89633fbg~gAAOSwTOxfoFD0 ) can deliver up to 18VDC at 5A. And if you need more current, you can parallel two of these easily, as they have tracking link connections that lets one supply control the second. Price on the one listed is a bit steep (you should be able to find these under $200), but they provide dead-quiet DC on output...very little junk on that DC feed to cause the TPS to get noisier.