B+ fuse value

[Randall]

I am working on a heavily modded Sunn Spectrum I amp running two EH KT88s. The work is very well done. It has a HV fuse holder with no label and a 2 amp SB fuse in it, very well could be an addition. It seems to me this is excessive. External bias points are labeled "bias to 50 mA max per side, mV scale = mA"

Should this be a 500mV fuse?

[g1]

I think 500mA Slow should be sufficient. 5AR4 rectifier is rated at max 250mA output.