Mobile Paladin build advice

[tenfoldGambit]

So I'm crafting a character for an upcoming homebrewed 5e cyberpunk campaign and I'm having the classic problem of fun/optimized. My DM isn't overly punishing, but I don't think they plan on going easy on us this time. My current build is as follows:

Human Vengeance Paladin
Starting stats
STR: 16
DEX: 14
CON: 14
WIS: 10
INT: 9
CHR: 16

Free feat (as per DM): heavy armor master (slightly modified to scale over levels)

Fighting Style: Tunnel fighter

Weapon of choice: greatsword

Planning on dumping my first ASI into STR, and then at level 8 taking the Mobile feat which might seem like a weird choice, but hear me out.

I'm trying to go for a mobile OoV paladin that uses tunnel fighters bonus action (when available) to get more op attacks. Due to the level 7 OoV paladin ability, I get to move up to half movement speed after an opportunity attack as free movement + the bonus to movement from mobile gives me a slight boost to that. With good positioning I could potentially get attacks off on every moving enemy every round. Heavy armor master is there to mitigate the lack of AC and defensive options. Though I've been looking at swapping it for GWM for the +10 damage or maybe Sentinel for the lockdown though the character isn't super tanky. Defense might also be a more rounded choice for fighting style but I'm not sold on how fun it is.

I'm not sure how well this is going to work in practice and I've discussed with my DM but they're not much of a hardcore rules person/optimizer.

Anyone tried tunnel fighter in game to any good effect? Thoughts on how this setup might play out in practice?

Thanks

[zylodrizzt]

If it's working as you think it works is recommend polearm master instead of another because you will only get oa against things moving out of your threatened area. Might I suggest war caster and magic innitiate for booming blade so it looks more like this.

Turn 1: move close but not directly next to and dodge or attack with reach weapon use bonus for tunnel fighting

2 melee monster turn.
1st moves up so you give him a smack with booming blade. He either moves and takes damage or tries to get next to you or allies. I believe you can only smack him once though on a turn.
2nd now moves up and you do the same. Rinse and repeat. Mobile helps too so you can get out of there if need be.

[SaA]

Make an Orc its racial ability is a bonus action Dash

[The Shadowdove]

Mobile is an obvious option. Aside from the name, each ability screams a mobile melee character that does whatever the heck they want.

Pair that with a polearm or whip/darts and you're an annoying in/out fighter.

Sentinel can only add to your stickiness and infuriate your foes.

Want to be even more annoying, get the booming blade cantrip somehow and make them take damage for chasing you whenever you aren't smiting things.

Shield mastery with mobile is also funny. You get to shove them prone with a bonus action, which takes 1/2 their movement just to stand, have advantage on your attack, then can run away.

[tenfoldGambit]

Hmm... While having dash as a bonus action would be fantastic, I'm fairly limited in what races are available to me.

I like the whip idea. That could be insanely fun. Thanks!

[SaA]

Hmm... While having dash as a bonus action would be fantastic, I'm fairly limited in what races are available to me.

I like the whip idea. That could be insanely fun. Thanks!

what races are available ?