Esoteric polymath bard learn spell success rate

I’m building a polymath bard and am interested in the flexibility that the spell book offers. However it seems, looking at DCs for learning spells, it will always be quite hard and will result in a lot of failures. What are peoples experience with this and how would you improve sizes rates? Pumping INT and Occultism skill is the obvious routes but is this enough on its own? If not what else can I do? Or should I not worry about it and just accept that failure will happen often?

Also thinking with focus on INT and Occultism adopting the enigma muse as well might bring sone good synergies. Any suggestions for this build path?

You usually pick the best spells each level for you repertoire. So you're usually in no rush to add top level spells to your spellbook. Your chances of success increase dramatically if you learn spells one or two spell levels below current maximum. Also keeps the gold cost more manageable. Learning multimple top level spells can get expensive rather quickly.

Other than that, just accept that you'll fail every now and then. Get Magical Shorthand if your campaign has long downtimes to make good use of it.

And as a bit of a homebrew-y possible solution: You could also ask your GM if he'd allow you to take Lore (Occult Spells) as a very specific Lore to learn your spells at a lower DC. Getting this and having it auto-scale with Additional Lore would probably help a lot.

Assurance (Occultism) is the most reliable way to get it done while still allowing you to flaw int and str for an extra boost in a more meaningful stat. You'll be able to scribe your current spell level at even levels (3rd level spells at character level 6 for instance), though you'll probably be delayed at some points since performance is prioritized for lingering composition (which just about every non-maestro grabs with multifarious muse).