One of the big benefits of a magus/maga's talisman is the ability to enchant effects at range personal that can target the magus. This allows them to circumvent parma. It allows them a range personal InMe effect to enable mentally triggered enchantments.
Of course if someone else ever gets their hands on the talisman none of these range personal effects will function for them.
There is some mention in the books of talismans being passed down to others.
From those those two facts, it seems likely that at least some older magi seeing their eventual demise approaching intstill muto vim enchantments similar to wizard's reachinto their talismans. These enchantments would raise the range of personal enchantments to range touch.
That's a bit of color that one could add to their game, perhaps to foreshadow the passing of an NPC.
I approached this from the opposite direction. Houses that made a habit of stockpiling the talismans of dead magi developed the Talismanic Writ.
Talismanic Writ: This is a single-use charged item, traditionally a scroll emblazoned with the name of an archmagus. When it is read, the Writ creates a magical shell around the user which makes him appear to be, for the purposes of a Talisman, the named archmagus. A Writ only works for effects in the Talisman with a level equal to or less than the Writ's level. Talismanic Writs typically have Duration Moon (+3 levels).
Was there a story or two wrapped around that idea, that you played?
It seems a cool minor breakthrough, that folks who don't know would like to learn, that in itself is enough to wrap a story around.
What sort of things did the original researcher have to do get insight into it? Capture the new formed ghosts of elder magi at the moment they passed from this world? Tear apart one or more talismans that were made by others in order to see how their individual bonds with their magi differ? What sort of simmering conflicts did the researcher leave in her wake?
It was an apprentice saga, you are kind to ask! The player characters were 9 years into their apprenticeship in the Greater Alps and were sent to rescue Hugh of Flambeau from a clan of Slavic vampires. This was something of an “off the books” operation, as Hugh had gone rogue and the tribunal was otherwise busy hunting down diabolists. I wanted each apprentice to get something special from their masters as preparation for this mission, and I had a Tremere. We already know House Tremere keeps the talismans of its magi handy as an aresenal for special occasions.
So I gave the Tremere PC the Wand of Nestor, his great grand Parens, I think, which had a panoply of effects as high as level 75. His Parens told him “come back with this wand or don’t come back.” Using the writ gave the PC warping.
I guess I decided it wasn’t a breakthrough, just an example of a “magical shell.”
that still leaves open quite many interesting and useful options.
For example imagine a magus with a talisman that has effects at personal range that are meant to "buff" the magus who has the talisman. That magus then gets old and upon feeling death coming decides that they want to pass on their talisman to someone else, an apprentice, covenant-mate, amicus whatever. On the face of it most of the spell cast at Range:Personal by the talisman used to enchance the magus owning the talisman would be rendered useless by the death of the original magus. However the magus can enchant a MuVi spell to increase the range from Personal to Touch on these spells, in the talisman and suddenly the talisman is much more useful to others.
The big idea of the first post is that stuff like a range personal intellego mentem effect that is used to as a linked trigger to a half dozen other enchantments could be used after the magus' passing if they too the time to enchant a muto vim wizard's reach into the talisman.
But that's not strictly necessary. The inheriting magus/maga can cast the Muto Vim wizard's reach (mentem) themselves. Yes, I agree that this is cumbersome, but it's certainly much faster than waiting for the former owner to enchant the range booster for you.
As after the bequeather's death no other magus can instill an effect into his Talisman any more, you need then either Breakthroughs or such cumbersome workarounds.
The InMe effect is typically of the kind of ArM5 p.99 box Constant Effect Devices - and then it can be MuVied only precisely at sunrise and sunset, when magi already would have to restore their Parmae and retrigger/recast other D: Sun stuff.
The effects triggered by the InMe might also be R: Personal. So each of these would have to be MuVied separately exactly when the InMe triggers them.
Being a nice legacy hunter, sweetening the last years of magus Senex Venerabilis and inducing him to put the last MuVi enchantments into the Talisman, might result in getting a far more useful item.
I disagree with the take that InMe enchantments would often be constat duration. Constant duration range personal effects would be quite rare on talismans. They would warp the holder. These effects would instead be enchanted at duration Sun or Concentration and activated when the magus feels the need.
As the problem in the OP is from your game, you are well in your right to frame it as you like.
Wouldn't a R:Personal effect with (ArM5 p.99 box) constant duration and triggered by touching the Taliman be far more efficient, though: it would cease to work - and warp - some hours after the Talisman is dropped, but activating it would not need concentration or crowd the busy time of sunrise/sunset even more.