Make Chalice of Harmony passive work on Manaless champions

Chalice of Harmony is a pretty interesting item due to its passive, Harmony. This item has two rather unique upgrades as well, Athene's Unholy Grail and Mikael's Crucible. While I really like these items I feel like some champions that would be able to use these items unique qualities fairly effective are locked out of them because of the Harmony and Dissonance passives.

I am not asking for the mana regen to be removed from the items, or for manaless champions to be given special treatment from these items. I just feel like the game could make it so that when manaless champs buy the items they could get the benefit from the passive without much of a change. I think that if the champion is manaless the passive could give the bonus health regen, or AP in the case of Athene's, for X% mana regen that they have bought rather than them getting nothing out of it.

There are a few niche examples that this could come up in more naturally, but it would also allow for various off-builds for a few champs.

The first example I want to use is support Mundo, running guardian and font of life. Due to his health stacking font can actually regen quite a bit for his team, and buying Mikael's can often be temping because of that. But so much of the gold efficiency is lost from harmony not being active, 300 gold of health regen that you usually are getting from the item just isn't there simply because you are Mundo (or a different manaless champ). If you were to also buy a redemption, which grants 150% base mana regen, you are now missing out on an addition 450 gold of health regen that mana champions receive. Just with that two item combo, Mundo is now missing out on 750 gold in a stat that he enjoys just because he is manaless. He already isn't gaining from the 1250 gold worth in stats that goes towards the mana regen itself, I don't see why he should be further punished by not having access to the Harmony passive. To put that into perspective that is a 2000 gold stat lose coming from a item combination that costs 4200 gold.

The second is an item + champ combination that is very dear to my heart, Mordekaiser with Athene's Unholy Grail. The blood charge passive has a lot of synergy with his kit and can change his role in a team which allows him to be used in more team compositions. Much like with the Mundo example, this comes at a major cost to the cost efficiency in stat from items. Athene's Grail, with no other items, gives mana champions 2543.33 gold in stats without it's passive. That's a 114.01% cost efficiency on the item overall, not including the blood charge passive. Since manaless champs like Mordekaiser don't have mana, those stats don't do anything which means you are dropping 500 gold into nothing. That would be fine and reason. However since the dissonance passive, which converts bought mana regen into AP, also doesn't activate that means Mordekaiser would lose another 20 AP that mana champions would get, losing another 425 gold in stats leaving the item at 1459 gold worth in stats and a 69.4% cost efficiency. That is a huge drop from the item usually. If the chalice line passive actually applied, it would put the item with a reasonable 2043.33 gold in stats giving it a 97.3% cost efficiency.

Is there anyway that this passive can be changed in the way I suggested so that players are able to feel better about buying this line on a wider variety of champions?