Best way to protect searcher’s equity stake from post-investment dilution

I understand in add-on strategies, folks often agree to protect the searcher from dilution up to a capped $ amount of equity (i.e., the first $15M) and after that there is dilution if there is additional equity and the searcher doesn't contribute.

I'd imagine you could finance a significant portion of any add-ons with debt though too.

Thanks guys! Super helpful. As an investor you’re often told that it can be much better to have a smaller piece of a bigger pie rather than the inverse but the opportunity I am looking at implies using the target as the foundation for many sizeable add-on acquisitions that will mostly be financed through additional equity raises and I want to make sure I don’t end up in a position where I am disincentivized to execute on these acquisitions.