I have a house rule for wizards that does something like this inspired by 4e and my own ideas…
1st: Implement Mastery
optionally replaces Arcane Recovery
You can use an arcane focus – a crystal, orb, rod, staff, or wand – to exert greater control over your magic. Choose one.
If your implement is ever broken or lost, you can bond with a new one after a long rest.
Crystal of Concentration
While concentrating on a spell while wielding a crystal as your arcane focus, you can expend a spell slot when you make a concentration check, gaining a +1 bonus per level of the spell slot expended to your check.
If your crystal is removed from your person, or you believe it has been removed, you immediately lose concentration on any spell you’re currently concentrating on.
Orb of Imposition
When a creature fails its saving throw against a spell you cast while wielding an orb as your arcane focus, and that spell involves repeated saves, you can expend a spell slot to impose a penalty on their subsequent saving throws against the spell. The penalty equals the level of the spell slot.
If your orb is destroyed, you suffer a level of exhaustion.
Rod of Metamagic
Choose one of the following metamagic options to imbue your rod with: Careful Spell (use INT instead), Distant Spell, Empowered Spell (use INT instead), Extended Spell, Subtle Spell, or Transmuted Spell. When you cast a spell while wielding the rod as your arcane focus, you can expend an additional 1st or 2nd level spell slot to apply the metamagic to your spell.
If your rod or a spell you cast while using your rod as an arcane focus is dispelled, lose a 1st or 2nd level spell slot, which you regain after a short rest.
Staff of Defense
While wielding a staff as your arcane focus, you can use an action to expend a spell slot and empower your staff for 1 hour. While empowered, your staff gives you a +1 AC bonus per level of the spell slot expended and functions as a magical weapon. However, each time you are attacked, hit or miss, reduce this bonus by 1.
If your staff is destroyed while empowered, you are knocked prone and suffer 1d6 force damage per remaining defense bonus.
Wand of Accuracy
When you cast an attack spell while wielding a wand as your arcane focus, you can expend an additional spell slot to give yourself a bonus to your spell attack roll. Each level of the spell slot that you expend grants you a +1 bonus to the attack.
If your spell is countered or you face a creature with Spell Reflection, your spell is reflected back at you with the same bonus to the attack roll that you had.
