I've tested the hold to charge method and haven't run into any issues. With C2F selected, dying while it's charged does indeed cause an autofire bug if you switch to another weapon after respawning (the LR doesn't autofire upon respawn). However even if you fire the LR before dying you will likely run into the same autofire bug. After doing some more testing I may have figured out what's causing them.
If you charge up and fire the LR and click to respawn, you will very likely have the autofire bug at respawn. However if you instead press Space (or something other than LMB) to respawn, the autofire bug doesn't happen at all.
If you charge up and LR and die (not firing it) and click to respawn, you will very likely have the autofire bug if you switch to another weapon. However if you instead press Space (or something other than LMB) to respawn, the autofire bug will affect the LR at respawn, as well as your other weapon. In other words, you don't have to switch to another weapon to get the autofire bug. Your LR will start firing immediately.
So I'm pretty sure spamming LMB (or whatever your firing button is) to respawn is the real culprit here.