I fully agree with the 'long term' aspect of it. There are plenty of more useful short term mods on the way though, many of which can be utilized later on.
The earlier mods that I'd recommend in order are:
You may also want to consider adding a BLTouch or 3DTouch ($12 Chinese clone from aliexpress), when you're ready to do firmware upgrading (required to use one). You can also build a just the Voron "Afterburner" and direct drive clockwork out of the guts from a BMG and slap it on your gantry. There are also lots of alternative options for direct drive conversion as well, if you don't intend to go the Merc1 route later.
I've used these POLISI3d brand heatbreaks with good luck with the stock ender MK8 hot ends. You probably don't really need a two pack of them, I'd heard lots of people recommend trianglelab on AliExpress as a good source too. Use computer CPU heatsink paste to get a good thermal connection from the heatbreak to the heatsink, and it will help keep things running nice.
Keep in mind, with the "all-metal" conversion, your printer's retraction needs will change somewhat dramatically. I dropped my retract from ~6.5mm to ~3.75mm with the swap. If you don't reduce your retraction, the excessive over-pull of filament will cause constant jamming problems.
I print Hatchbox PETG at 235 or 240 depending on the color, first layer 5C hotter, at a print speed of 30mm/s for walls and outsides, 40 for infill, and run 50% fans after layer 3 (but I also print in an enclosure... 30% is probably fine for open air.)
This is what I bought and can confirm works. https://www.amazon.com/gp/product/B08TCD4M1S
This one
https://www.amazon.com/dp/B0899GP2KD/ref=cm_sw_r_cp_apap_aumaXstiZVrAR
Cheap, comes with 5 standard and 5 all metal heartbreaks. Quality is so so. Or
https://www.amazon.com/dp/B08TCD4M1S/ref=cm_sw_r_cp_apap_CGfRhMWsThA67
The latter will require nozzles with longer threads, like
https://www.amazon.com/dp/B07NTR3M4W?ref=ppx_pop_mob_ap_share
instead of the stock nozzles, since you can't screw the heatbreak in as far.
Heat the hot end to at least 70C before you unscrew anything. Doing a cold pull beforehand will get most of the old filament out and keep things clean. Don't forget to redo your Z0 height.
FWIW the V5 block on the Q5 has M6 threads.
I bought one of these and put it in. Works so much better than the PTFE tube. So many fewer issues over time. And same as for any all metal hotend. Make sure your heartbreak cooling is perfect.
https://www.amazon.com/dp/B08TCD4M1S/ref=cm_sw_r_apa_gl_i_33B6TERXEVP9Q10JSRV6_1#