If you are already a "sampire" then IMO under no circumstance should you nned to imbue HLL, as VF already gives you effectively 120% HLL. HLA is, by my crunching of the numbers, not as useful as HLD.
Depending on your "average" purpose when using thie "general" purpose weapon, you rarely need HLA. Against any regularly spawning mob, I'd take 100% HLD over 50 HLD and HLA.
Putting 50 HLD on there, and then going for a proper reforged/imbued helmet instead of the reading glasses is probably the smart move.