Vicious Projectiles and other support gems with "Attack" tag don't work with Phantasms

I've tested following support gems with Soulwrest staff and cross-referenced it with information that is being provided on character screen.

The following gems seems to have no effect at all:
Vicious Projectiles Support - even when the phantasms are dealing projectile physical damage and all other projectile support gems seems to be working just fine. The only difference is that this one has "attack" tag and so it doesn't work at all.

same goes for other gems with "attack" tag, the ones I've tested are as follows:
Maim Support, Withering Touch Support, Faster Attacks Support, Life Gain on Hit Support (funny thing, because Life Leech Support works just fine, it doesn't have "attack" tag, though), Elemental Damage with Attacks Support..

I believe that the original intention was to

It seems that any and every gem that has "attack" tag doesn't work currently with physical projectiles that are being used by Phantasms.

Soulwrest says it triggers a level 20 Summon Phantasm.

Summon Phantasm on Kill says it summons a minion "which uses a piercing projectile spell".

If the minions do not use attacks, attack modifiers won't affect them.

For example, Vicious Projectiles says that it "Supports projectile attack skills."