I have an existing Debian 9 installation on a 2 TB GPT formatted internal SSD/SATA hybrid hard disk on a brand new Acer laptop. The entire Debian install takes up a mere 600 GB of the hard drive. No other distro nor OSes are on the remaining 1.4 TB space. During the initial Debian installation, I set aside only 250 MB for /boot/efi FAT32 formatted partition which resides on the last partition of my Debian install i.e. /dev/sda7.
On top of Debian, I am thinking of installing several other distros to fill up the remainder 1.4 TB currently empty spaceas well as on an external 2 TB portable drive. I understand that different distros and OSes can share a common, bootbable ESP ala /boot/efi. However going through severalof the Installation guides for Manjaro, Solus among others, I discovered that they mostly seem to recommend a 512 MB /boot/efi. My question is can I simply and safely resize my /dev/sda7 from the existing 250 MB /boot/efi to 512 MB in say, the Manjaro's Calamares (or any other distro's partitioning portion of their installer) installer? Will doing so render my Debian unbootable? What precautions do I need to exercise if any?