Baardvark, As someone who is planning on converting their 5E campaign to DOS2 I appreciate the work you've done and the feedback you've been giving.

To me it's more about the feel of it than actually converting the core mechanics to match 5E exactly. A bit of a disclaimer: Take my input with a grain of salt. As much as I love D&D 5E, I actually don't like class systems and did a classless conversion for my home game. That said I love the feel of 5E, the D&D spells & abilities, The races etc. I do like how you pick a "class" at the beginning but can adjust it.

I think most of the feel of D&D can be added in with races, skills, talents, and items.

Here i what my thoughts have been putting my 5E into DOS2.

Attributes. (also scaling & balance)
Honestly they are close enough for me. I'm not too worried about what they are called and I worry that changing what they do will make it harder to put together encounters as you get higher in levels. I like when casters can benefit from all the mental abilities and melee benefit from all the physical abilities.

Combat.
I actually like the AP system over set actions. It brings be back to pathfinder when I could do full round attacks because I wasn't taking time and energy to move.

Armor and Saves.
My main issue with the system is once armor runs out it's just a back and forth CC game. I like the hybrid resist system but I would also like you to be able to save each round to reduce status effects by 1 level i.e. frozen to chilled. It should probably cost an AP to roll for a chance reduce status effects.

Classes & leveling
As I said before I prefer a classless system and quite like the DOS2 system for that. There are a lot of things missing as far as class features and abilities. I think this could all be added with talents and skills.

Classes.
As stated above I think most missing class features canbe added with talents or skills. You already did some great work with the bard. I think monks can be created by adding some skills and possibly a new class of equipment if that would be easier than tweaking it another way. Monk weapons could be added and their skills would require monk weapons. For unarmed maybe gloves that go in weapon slot and take away the glove slot.

Scaling and balance.
I think with a complete overhaul of the system putting together encounters might be a lot harder. Then again I'm not looking for this to turn into 5E exactly but just get more of the feel in there.

Proficiencies
I think the civil abilities and skills cover just about any bonus the GM would want to give someone on a roll so these work for me.

Talents/Feats
Going to need a lot added to cover class abilities and feats. I think this is where a lot of the flavor of D&D can be added.

Concentration
I don't think there a re many things this would impact.

Advantage/Disadvantage
The game already has things like high ground and flanking. I would honestly leave this as a manual role to be used when the DM sees fit.

Death and Unconsciousness
I would love to have death saving throws. With this I would greatly tweak resurrection scrolls. Make them take more AP, Shorter range, etc.

Conditions
As touched on before I would like to have a way to remove or downgrade CC each round instead of getting auto skipped. I was actually using your Bard mod for inspiration and thinking up a status removing skill for each race like the lizard shedding skin thought I would have them weak to physical after, dwarf would get stone skin limiting movement and AP after, Elves would get absorb lowering their resistances, Humans I don't know yet.

Resting.
This is a tough one for me. There is already a resting mechanic but I don't like how you can just pop down and do it whenever you want. I would be nice if you could implement a timer or something on bed rolls. I'll probably just remove them from my game. I would be nice if I had the option to give me players a short rest automatically. I plan on source points recharging with a long rest. The ability to give them a short rest to recover armor / health and a long rest to restore that plus source would be awesome. I don't what them to just be able to hit the bed roll and be recovered. There might be added feats like luck and so on added with feats. I don't know if a check box to track the uses could be added or something then reset on the long rest also.

Races,
Please someone add the D&D races. Thanks bye.
But really, I sould love to have more player races. My biggest issue right now is the same one I have with D&D so it might not reply here. I hate races having stat bnuses and feel that all it does is limit race / "class" (I'll call it skill set choices) at character creation.

I actually got this game because of GM mode so right now I'm just in a holding pattern for release and the editor and playing to know enough about the different skills and abilities to build my campaign.

I guess for someone that claims to love D&D a lot I sure did throw out or trash half the things about it...