Shopify - Anyone have excellent experience in variants & app creation?

So I have a shopify store with many products, I'm doing a new thing with each product will have many different variants, I tried almost all the stupid variants apps on shopify but they are limited to what I need them to do, one is doing it OK for me but still I need a better one, I was wondering if there is a possibility of someone creating an app or fixing an existing one that can work with our shopify store in regard of variants? I don't want to do a major theme change as website is going through major SEO optimization now and I don;t want to mess with this, otherwise I would have moved it to WP/ woo commerce if WP/ woo are better option for what I'm looking for.

Please post your experience in regard of variants and shopify, or even better: post your experience of moving a shopify store to WP/ Woo and the effects on your SEO at that time when you moved the site, did it affect the SEO negatively, how did you do it safely?

Didn't know where to post this, moderator please move it where it belongs if needed