Yes but if you're talking about RL Money->Credit traders being a thing, they would use trading commodities back and forth which people already do to transfer Credits to friends or alt accounts. They wouldn't do it with the bartender even if the bartender had a higher capacity because the Cr values are just so low in comparison. The most expensive thing at the bartender is 125,000 Cr galactic average, which at 1000% can become 1,250,000. But the ones that cost that are fairly hard to come by. Meanwhile Tritium is 50,000 Cr /T galactic average, and 1000% takes it to 500,000 Cr/T. However you can much more easily get a full Type-9 load of it 790T. So that becomes 395,000,000 per switchback.
While if the bartender could carry 1000 of the 125,000 Cr items, getting 1000 of them is another question. Doable, but nowhere even remotely as quick or easy as 790 T of Tritium, and furthermore since 1000 already is that max carrying capacity, the player getting the money transferred to them by the real world money trader would have to completely empty out their on-foot materials locker of anything of that type to be able to even use that as an option. The 1000 of 125,000 Cr at 1000% is 1,250,000,000 it's just so so so much more effort that can simply be overcome by just a bit over 3 switchbacks of Tritium at 1000% on the commodity market instead, and that's something you can just go buy at a station en masse.