No project can support you just for content creation. Please understand that this is a money making scheme. Its clear that with premium only your support will be increased by %. Your overall activity on the chain will determine if you are eligible for support. As far as I am aware then premium has not mentioned anywhere that you will get support just for being a premium user.

Is it possible to guarantee support from the project at least twice a week?

again there is no guaratee for anyone including premium users. I see people getting support 3-4 times in a week but its because they have spent time here. Hope you get what I am saying. Like many other you can also get support but stop trying to focus on upvote and just earning money.