Business can start differently and with different resources from human resources to financial resources, they can have manual or automatic deposit credit nd withdrawal approval as well as processing for users. With time, if their business don't fail or close but expand more, they almost have to move from manual processing to automatic processing. It's natural business growth as with bigger company, more customers, more demand on deposits (credit to account balance) and withdrawal request, it will gradually become impossible to handle these things manually.
It's true for all business not only Spinly.
I think Spinly Casino knows this very well. I figured out that they are not new to this place. They have another casino, and the name of the other platform is Bspin. They have been in this forum before. If a company has been in the same business for a couple of years, I am sure they know how to operate it and what is better for them. I think they will improve their service in the future.
I think players care about the withdrawal speed. So, I would suggest that the casino focus on this while it focuses on other developments. Withdrawal speed and the bonuses make players loyal to a casino.