D&D still required a free hand for loading even with Crossbow Expert letting characters ignore the property, so two crossbows and multiple attacks with each would not work in D&D, but a character with Crossbow Expert could make multiple attacks with Extra Attacks with a single crossbow, or that and a additional Bonus Action attack with a Hand Crossbow, assuming they were not using a shield or a second weapon. This was not clearly spelled out in D&D 5e, I think it was clarified in one of the columns from the designers. Level Up is a different system, so it might have a different take on what "ignore the loading property" means, however.Machine gun archer
Fighter lvl 12 Sharpshooter, - 3*ASI, Extra attack 2, Archery Fighting style, Shoot in melee
Rogue lvl 2, Combat tactic sniper: + prof to damage
Feat - Crossbow expertise, no loading property on crossbows
Feat - DeadEye 2x prof to damage,
Dual fight with hand crossbow doing 3 attacks with action: 1d6 + dex + 3*prof damage and 2 attacks with bonus action: 1d6 + 3 * prof damage
Alternatively with bow if your group is silly enough to allow "Press the attack" with ranged weapon targetting a foe next to your ally that does not want to do "Fall back" risking an opportunity attack:
Bonus action "Press the attack" granting advantage on your attacks doing 3 attacks with action: 1d8 + dex + 3*prof damage
Takes a long while to come online and most campaigns never reach tier 3 so not that useful.
Any more tricks to boost archery?
Even with only one Bonus Action attack for a Hand Crossbow instead of two from the Level UpTwo Weapon Fighting rules, Level Up ranged builds do have easy ways to out-damage those in D&D. The Rogue option to add proficiency to ranged damage alone is huge.
Elsewhere I was told Press The Attack was not meant to apply to ranged attacks, but the initial PDFs did not reflect this. It may get changed later to note it is melee only and the defender using Fall Back does not provoke opportunity attacks, but it is unclear if that is only "from that attacker" or from "any attacker" who might have threatened them when they used Fall Back.