Question about Ad Customizer Feed item Limit

[kevin...@interactiveh2o.com]

We have an automated tool that sets keyword ad parameters based on information from external sources that we are planning to migrate to ad customizers in the next month or so. One of our concerns is that unlike ad parameters, feed items are limited to 400,000 per account. Since the data we set generally varies by keyword within an ad group, we could potentially run into that limit when running the tool on the largest accounts we manage. Since ad parameters are being phased out, is there any plan to relax the limit for ad customizers so they could potentially be used to set keyword-level values across a large account as ad params so currently? Otherwise, do you have any suggestions on alternatives to how we might achieve the same result as our current implementation without having to limit the number of keywords covered?

Thanks,

Kevin