Ok, so the post you made for reference:
Well, the devil's in the details. Scenario two is indeed preferable as the less-bad option if the "fix" for Scenario one is no fix at all. Or makes the situation worse. And a topic like "how do you fix MagicRun" goes back to the beginning. If it WAS an easy fix, wouldn't it have been fixed by now?
Sure, but the baffling part is why haven't they just balanced it? I think it easy an easy fix for any optimizer. Hell I could legitimately balance it appropriately, right now in 10 mins, with a single post. Speaking for SR5 on the core system from the CRB:
Magic Attribute
- Maximum rating at character creation is 4.
- Initiation increases the cap as normal, to an absolute maximum of 12.
- Maximum Initiation Grade is 8.
Resisting Magic
- Every full point of essence lost to ware adds one additional die to spell resistance pools. Does not stack with the magic resistance quality or the racial spell resistance of gnomes, fomorians, ect.
Mystic Adepts
- Must choose one of spellcasting, summoning, or enchanting, like an aspected mage. They may not use the other two skill groups or options.
Spells
- The maximum number of spells a spellcaster may know equals their magic attribute x2.
- Cost 10 karma each, rather than 5.
Spirits
- Do not gain hardened armor, instead gaining armor = to force.
- Completely remove aid sorcery, spell sustaining, and spell binding from bound spirit options.
- Cannot be oversummoned without metamagic.
- Spirits higher than Force 8 always get to simply choose to heed a summoner's call or ignore it, no rolls required.
- You can never have more than one spirit actively participating in combat. You can have more than one spirit engaged in non-combat tasks, however.
Metamagic
- New metamagic: each time it is taken summoner can summon spirits with a force one higher than their magic attribute. If you are already able to summon a spirit of Force 8, each instance of this metamagic instead allows you can add one additional power to said spirits.
- Quickening: the maximum number of spells that can be quickened on a single creature or object is equal to the highest magic attribute of any awakened characters who have quickened a spell on said creature or object.
Reagents
- Can only be used to ignore the force/maximum hits limit of spells that effect the caster his/herself, rather than ignore the limit on any spell.
Foci
- Have a maximum rating of 4.
- Only rating 1 and 2 foci can be crafted. Rating 3 and 4 are reserved for artifacts and/or other objects of historical importance.
- Cost quadruple the karma and nuyen listed.
- Ki foci totally reworked: 1 PP worth of powers per rating, costs equal to power foci.
That was easy, and it will work. Some people just might not like the specific changes, but that will always be the case.
Stuff I agree with you on:
Spirits are OP and need a beatdown with the nerf bat.
Spells are undercosted and should cost more karma.
Mystic Adepts are stupidly OP in 5e. (note this is a 5e specific problem... they are very much less problematic in 4e and 6e)
It's too easy to get dice pools big enough to trivialize drain.
Specific proposals that I don't necessarily agree are necessary/addressing the problem of MagicRun:
Nerfing max MAG values (inelegant rule and doesn't parallel any other preexisting mechanics)
Needing metamagic to unlock oversummoning (if drain is fixed, and spirits are nerfed, then oversummoning is fixed!)
Capping Initiate Grade (seems pointless. the problem isn't how many metamagic techniques you have, and a stupidly high Initiate grade without a correspondingly high MAG is just a laundry list of extra metamagics you know. And if you have the karma to push your magic from 6 to 7 to 8 to even higher... bully for you. It's 75 karma to go from 6 to 8 MAG, and that's not even including the initiation costs. If you have that much karma and that's what you want to spend it on, I don't see a good reason to prevent it.)
Reagents: I don't really think in terms of 5e anymore, and talk about mechanics involving limits just don't matter to me as much anymore

Certainly not helping balance MagicRun in 6th, at any rate.
Things that I think are problems that your proposals didn't address:
Absence of a hard ceiling on how big a dice pool can be/how many bonus dice you can stack.
Related to above: Drain being too easy to fully soak. Also, I'd like to see some number of boxes of automatic, unsoakable drain when you overcast/oversummon.
5e specific problem: Too much AP on high force spells.
Too many GMs allow too much information to be discerned from astral reconnaissance.
LOS range. C'mon.
And let's have some cover penalties apply to (all) hostile spellcasting when all you can see is the tip of the target's pinky.
Alchemical Preparations are too hard for mundanes to employ. It's fine that mundanes can't make them, but they ought to at least be able to fully employ them.
Too easy/fast to erase astral signatures.
Too much ambiguity with regards to subject, target, and cross-planar sorcery. (sustaining, and effects) Details change by edition, but at least 5e and 6e have this in common: far too many specific "well what about"s are unanswerable.