Hi. In this case, you sould use only Feature Box addons in the section or in the inner section (without any other addons).
Add your own class to the section.
Set margin-bottom to 0 in Feature Box addons.
And use following code:
(for SPPB-4, SPPB-5 Beta)
.feature-box-grid .sppb-row-column {
margin-bottom: 30px;
}
.feature-box-grid .sppb-row-column :is(
.sppb-addon-wrapper,
.clearfix,
.sppb-addon-feature,
.sppb-addon-content) {
height: 100%;
}
Result
This is the basic code. Perhaps additional code will be required depending on your layout. For example, if you want to use a button inside Feature Box Addon and that it sticks to the bottom.
For SPPB 3 the code will be different. First, you need to configure and know the number of columns in the section. Only after that you can write a code