DISCLAIMER: There is no guarantee that anything here is safe to use. Use at your own risk.
Linux 4.19.118 patches I have cooked up. Patches are intended to fit into a debian package rebuild of the kernel and/or modules, using the debian quilt patches framework. To use these patches on your own you will need to be comfortable enough with reading code and recompiling the kernel.

July 24 2020 - Autosize fragment size patch enables linux to fragment packets into more evenly sized fragments, avoiding any future re-fragmentation and keeping packet sizes similar.

July 24 2020 - Adds the netdev_dbg_ratelimited() function so that debug statement in some of the rest of the patches listed on this page work right.

July 24 2020 - Allow any MTU and clear DF VXLAN patch modifies vxlan to use the mtu of your choice, clearing DF as appropriate so as to fragment oversize packets (but deliver them). You would still probably want to use TCP MSS clamping on the interface. Feature is controlled via module parameters.
More recent linux kernel releases have a patch in this area as well, but I think this one is better and will probably port it forward.

July 24 2020 - Sysfs for VXLAN patch adds sysfs per vxlan interface specific files and directories.

July 24 2020 - This patch builds on the MTU and sysfs patch to allow controlling of MTU and DF behavior at runtime.

July 24 2020 - VXLAN VLAN aware Patch is for when you use vxlan to trunk multiple vlans in a single interface and you want the forwarding database to take the vlan into consideration. Feature is controlled via sysfs or netlink.

July 24 2020 - This patch adds sysfs files for vxlan vlan aware feature from previous patch. This patch depends on the previous sysfs for vxlan patch.

The following bridge patches are very relevant if you are utilizing Vmware Vswitch which until recent versions do not do mac learning, instead, you have to enable promiscuous mode which results in flooding every single frame back to the attached virtual hosts, including the frame just sent from it. This makes proper MAC fdb learning a challenge.

More discussion on the matter from a fellow who knows what he is talking about.

July 24 2020 - This patch adds paranoid extra checking to make sure that bridge flooding of BUM frames is not sent out the originating port. Feature is controlled via sysfs or netlink.

July 24 2020 - Bridge FDB Quiesce patch detects and controls when fdb entries are flipping between interfaces (likely as a result of behavior akin to Vmware Vswitch in promiscuous mode). Feature is controlled via sysfs.

July 24 2020 - Netlink functionality for FDB quiescing enables the bridge quiescing functionality to be signalled and controlled via netlink. As documented elsewhere, net/bridge uses the most netlink call numbers and bumping those up as well as recompiling the entire kernel is required.

July 24 2020 - Patches (and packages) for brctl and iproute2 utilities that work with the above kernel patches.