I don't see why not, particularly in instances where the Summoner possesses both the Goetic and the Theurgical skills.
There is a certain amount of synergy between Goetic Summoning and Spell Spirits. Particularly with higher might spirits that would otherwise require a Ritual.
Say that you were able to conjure Lasa Vegoia, and had her teach you a level 100 Spontaneous Spell Spirit, or are able to invent Spell Spirit spells above level 50 on your own. Lets assume, to be on the safe side, that you should summon it via theurgy the first time (via the Ritual spell you just learned). You got your pact for future dealings done and out of the way, the Spirit will no longer resist your calls...
Now assuming your Summoning total is up to the task, you can use Goetic Summoning to conjure up said spirit (you have it's True Name after all)...it wouldn't cost you a single pawn of vis, or all that time you'd usually require.
You could also arguably Summon Daimons via Goetic Summoning. Only limitation to Goetic Arts that I've seen mentioned are Dominion-aligned spirits. Summoning them this way would save you a lot of vis, but it is also debatable if they would gain anything from getting summoned this way, unless you include vis in the summoning or in the post summon offering. Consult your DM / Troupe on this one.
Ablation I think you can still use but you'd assume that you are also permanently losing access to a Spell Spirit you just spent season(s) or Lasa knows how many pawns of Vis acquiring. I doubt a Spell Spirit would have any skills or Virtues beyond the spell that it exists to cast. Sure, you could perhaps ablate the spirit to learn the power yourself, which I imagine would manifest like an appropriate Greater/Lesser/Personal or Focus Power. Sure, you no longer have to roll for such spells, but it would cost you fatigue.
The alternative usage would basically equate to a season of vis extraction with more favorable Arts (potentially higher payoff) with no risk to the Aura and would last much shorter, but you'd probably be the only one able to use what I assume would end up being Vis Prava.
As a Hermetic Magus, relying on Ablation for your longevity feels a bit foolish. You would be under a constant, detectable Infernal effect. Just use standard Hermetic Rituals. Characteristic boosters? They could be useful for that, but again, what are their stats?
Commanding feels entirely unnecessary imo. Spell Spirits will always listen to you after the first summoning and Daimons are usually all too happy to provide a single free service per summon and to bargain for more. Also Commanding or Ablating a Daimon is a plain stupid idea.
