For Fragger I’d recommend either the M91, M62, K51, or K63. Maybe B52 if you insist on using the BR-16.
M91 is great because you get drilled and spares.
M62 gives you explodydendron, though this card is overshadowed by the M91 these days, I still use it because I’ve had one in cobalt since 2015.
K51 is nice because you get focus and drilled, I sometimes lean towards the K63 for spares though.
B52 has double time so maybe not for you, I personally like it dt + the card has spares.
For Turtle, I like either the SM93 or SM51, for the SMG-9 and extender/steady respectively.
For the KEK-10 I feel the C91 is the best choice because you get drilled and spares, and for the Hochfir I’ve always used the K92 because of steady.
I don’t play Aura much at all as I dislike low hp characters, and I don’t very much enjoy any of her weapons, but on the rare occasion that I do play her, I use the BL41 because of get-up and extra supplies, or BL72 for drilled and potent packs.