Can you further explain what you mean by fundraising options because I'm not sure if you know, there's options to earn some revenue on Tapastic as well.
Are you offering ad revenue or a Patreon like option directly on the site, like Tapastic's old Support Program?
I do find it hard to take Mystory seriously when you're scouting for talent on a competitor's platform site for your own platform site. The more professional method is direct emailing the artists which would of taken more dedication and work on your end to track and find everyone's email (perhaps off of their official webcomic sites) The last new comic platform site to approach the Tapastic community, Becomics, actually did it right and sent emails to artists instead of scouting on the site.
Granted emails from platform sites are also hard to take seriously and can come off "phishy" too, but it would of put Mystory in a better light. I think the best way to approach talent to join your site is to find a few series that appeals to Mystory's brand, approach them with genuine personalized emails explaining who, what, and why, and accept that it'll take a good long time to gain a trusting reputation in which artists would be willing to give Mystory a try.
Personally, I'm limiting the amount of sites I'm on so I can make sure I have the time to properly grow an audience on them. Being on too many platform sites can stretch the artist too thin and make it harder to engage an audience. My personal comic site, Tapastic, and LINE are all I'm willing to do. I'm not wanting or willing to join anymore than that. Thank you for the invite but I'll be passing on the opportunity.