I was about to hang sh*t on those blade type circuit breakers, but noticed in time that they are manually re-settable.

I had some auto reset circuit breakers of similar type, but would never consider having them again. I was fault finding, something to do with solar charging IIRC. It was a nightmare, very difficult to track down. In the end it came down to substitution to find where the problem was & it turned out to be the blade type CB, confirmed by opening it up. The design was essentially a dished piece of metal which would 'pop' out when over current heated it sufficiently. Once cooled down it would return to it's default state, reconnecting the power creating a very difficult to track down intermittent fault. In this instance the culprit was poor quality construction. The 'dish' held in place by a rivet through it's centre was loose, creating a poor connection & excess heat.

Manually re-settable ones are a different ballgame. You can see when they are 'tripped', & they stay tripped until you reset them. For lower amps (15a, maybe 20a & below) they are a great alternative to fuses.

Higher amp versions would likely suffer the same problem as the higher amp fuse versions - oxidation on the blades resulting in resistance & heat build up without blowing - creating a fire risk.