Indeed, but don’t ask the users that flashed tasmota months or even years before you and running Tasmota Versions 5,6,7. They are essentially trapped and can leave there vulnerable devices running for ever or bite the apple and start essentially from scratch when they are not adventures in trying the “upgrade flow” 
Don’t forget that you navigated to both of the devices before in the browser, entered your password (hopefully) as well as entered the correct menu to start the ota upgrade.
As a comparison. With the esphome dashboard (running on ha for example) it is one click on “update all” to update all my esphome nodes in my network at once, we are talking about 90 devices here 
You can essentially get rid of mqtt. A nice way of getting your rf “payloads” into home assistant is (ab)using the tags so you can make use of this nice interface here for your rf thingies:
from the esphome side all is needed is the homeassistant.tag_scanned action
Another way to achieve the same directly on the esphome device without having anything configured in ha (like a automation or something) is to trigger the (ha) action directly inside the esphome node, with something like this (that is how I do it with my IR thingie) 
binary_sensor:
- platform: remote_receiver
raw:
code: 0123456789
on_press:
- homeassistant.service:
service: homeassistant.toggle
data:
entity_id: switch.tv_set
In theory (like already extensivly written in this thread) the native api from home assistant outperforms mqtt with it’s performance focus on low latency and efficiency.
In practices the lag you are experiencing could also be introduced from the RF part of the light switching scenario. 