I am sorry to hear that your expectations of support are not being met, as that is not what we strive for. Please keep in mind though, that here in support, we can only inform you of what our software is capable of today. If that does not meet your needs, you're welcome to suggest new features in our Feature Suggestion forum. However, please keep in mind that these will be evaluated by our product team and if greenlit, worked into our development plan and lifecycle.
I am also sorry that you are getting frustrated with spam, I would too. It is, unfortunately, a very frustrating part of running a website. I am happy to shift the focus of this support topic from word filters to how else you can prevent spam now that we have established why these bots can get around word filters.
Seeing as you are seeing this with sleeper accounts that haven't posted in a while or have no/minimal posts, you may wish to use our group promotions tool to kind of separate users who have no or minimal activity to those who do. You can then mod queue the initial group that has no or minimal activity for 1 approved post or whatever you see fit to remove that mod queue. You can read more on that here: https://invisioncommunity.com/4guides/members-and-groups/promoting-members-r313/
There is also Automatic Moderation where your users can report content and if it meets the number of reports that you setup, it can be automatically hidden. This is helpful if you have a small moderator team or when your moderator team is offline. This can be done in ACP -> Members -> Automatic Moderation.
Unfortunately, based on what you and a few others are reporting, there is quite a large spam attack going on out on the web currently. You may wish to analyze the given IP addresses or countries of the offending users and ban these at the network level with your hosting provider if you do not have real members from these countries. There are other solutions like CloudFlare which like you ban whole ASNs which may be of use as well.