Combat wheelchairs

[WaroftheCrans]

Also, am I the only one who's noticed that the heavily armored upgrade is essentially useless because you can only have 2, and the battering ram one is just vastly superior?

A wedge-shaped ram has been affixed to the front of your chair, covering your lower
legs. You can use this to knock down a target creature in combat. The parting ram works
the same way as the Ram action in combat but the target creature must make a
successful DC 15 Strength save or be knocked prone.
Whilst in the chair with this Upgrade affixed, you also gain a +4 bonus to your Strength
check when using the parting ram to break down doors. One other character can help
you use the parting ram in this manner by pushing you and the chair to provide extra
momentum (with your permission, of course), giving you advantage on the check.
This Upgrade also provides half-cover to the chair's user as it covers the lower half of
their body in much the same way a low wall would.
Cost: 10gp (a standard portable ram is 4gp)
Weight: 35 pounds (lbs)

A target with half cover has a +2 bonus to AC and Dexterity saving throws. A target has half cover if an obstacle blocks at least half of its body. The obstacle might be a low wall, a large piece of furniture, a narrow tree trunk, or a creature, whether that creature is an enemy or a friend.

Small but heavy metal plates are attached to the frame of the Combat Wheelchair to better protect it and the user's lower body.
This Upgrade increases the wheelchair's weight from 25 pounds (lbs) to 65 pounds (lbs).
You gain a +2 to your AC whilst you are in the chair. When you are not in the chair, you no longer have this bonus. If this upgrade is removed, you no longer gain a +2 AC bonus whilst in the chair. Whilst this Upgrade is affixed to your chair, you also have disadvantage on Dexterity saving throws and Acrobatic and Stealth checks.
Additionally, the number of Critical Hits your chair can withstand before needing repairs increases from 3 to 6.
Cost: 550gp
Weight: 40 pounds (lbs)
Armoured Plates cannot be used with the Upgrade 'Agile Suspension' or 'Suppression Tyres'.

So Parting ram has no restrictions, weighs less, costs considerably less, has no penalties, offers additional bonuses, and from it's half cover provides + 2 AC and +2 to Dex saving throws.

Meanwhile the only thing Armored Plates has over it is that it can stack with half cover, and takes the chance of a chair being broken in combat from 20^-3 (1/8000) to 20^-6 (1/640000000) per attack targeting the chair, assuming no crit range expansion or advantage. The chair was already effectively invincible (which is really dumb), so this does nothing.

Mounted sniper and Scattering tacks are entirely pointless (what's preventing you from just using caltrops or a light crossbow?) Additionally, the wheelchair explicitly counts as a mount, so that 25 foot movespeed is really 50 foot move speed with immunity to OA's.
The upgrades of the chair aren't balanced at all against the rest of the game or against each other, and have varying levels of logic and verisimilitude breaking.

Take the spider legs for instance: if you can make spider legs that can lift an entire wheelchair and its occupant and give it spider climb, you should reasonably be able to make a Doc Ock style backpack that weighs and costs less, and lasts for longer. But nope, this is wheelchair exclusive.

And lets not even mention the effects of beacon stones on a setting.

I have no problem with wheelchair bound characters in D&D, but this is just not the way to do it.

Edit: Oh right, merely by owning this chair you have become proficient with tinker's tools. I wonder, if you sell the chair do you lose the proficiency?