This is why I use Guardian Shard Cannons so often. Fully engineered frags as you describe have roughly equivalent thermal damage to C3 Shards, meanwhile, I'm satisfied with the armour damage provided by my twin MCs (Autoreload + corrosive OC MCs, C2 slots) and OC C3 Beam.
Definitely inferior overall DPS to the Frags, but, a cheap, no-engineering alternative that gives me that shield-punch I need.
I'm with OP. All Frags all the time.
No wait - I've got a pair of PAs with Target Lock Breaker as well, but 3 Gimpballed Frags with Double-Shot and Screening-Shell.
People keep telling me I'm better off with OverCharged Frags, and I've got a set of 3, but I just don't feel the use case.
I love Double Shot and the fast reload from screening shell. It's like BLAMBLAMBLAM!, BLAMBLAMBLAM!
I also use my hull strength as ammo, so lots of ramming and jamming close range brawling. Pretty entertaining if I'm in your wing.
My favourite thing is when a CMDR sees that I'm like 42% hull and rams me head on. I boost to meet him, and POW I drop to like 34%, but he's shields down and 83% and BLAMMITY-BLAMBLAM! Ouch! 50% - He doesn't have target lock and he's looking for an exit, and the Krait has permaboost so "Right Behind You, dude".
Frags - Yeah Bwoi!
Even got a ship kit to match the engineering and combat style:
Yeah the Ammo Synth to finish even one CZ is a pain, but even that kinda matches what I'm doing with this Krait.
Home Made, Jury Rigged, No Holds Barred, Scrappy annd D I R T Y*.
* - Look it's not illegal, but the Target Lock Breakers and being engineered HARD and COLD means other CMDRs are often surprised in combat.
Low Heat Profile, Silent Running, Target Lock Breakers, Heat Sinks, No Shields, - Yeah I drop off your Radar a LOT.