Misleading, I have a dual boot set-up with multiple UKIs that require ~300MiB each and therefore have a 4GB EFI part, there is no strict required size for a EFI partition and no it does not affect boot times. OP, If I were you, I would familiarise myself with chroot. When you resize your Linux partition to accommodate a larger boot partition (the first partition) often times partition UUIDs (unique universal identifier) have a quirk of wanting to change that then requires you to update your /etc/fstab to tell Linux where to look for all your partitions, without being able to directly boot your OS. Is it possible to grow your EFI and resize your Linux Part? Yes. Is is an easy risk free process? Absolutely not. If you prefer doing a clean instal with less manual work I would follow the resize and reinstall all approach described above.