So starting from the point that armor is currently doubled and most weapons, with Fast Fire, modules and quirks factored are above ~250%, then armor could see a nice 50% boost at the minimum. Here's the original setup:

So using Spiders as an example, it currently has a max of 210 doubled. So if we round up with a 2.5x boost from 105 then we get 263.
So the mech can see a boost of 53 units of armor accordingly. If that is distributed to the legs and torso that would be a help to the mech.
(And such a change, if we can have these sorts of boost rolled into the base stats then Standard Armor would sit at 40 units per ton, IS Ferro would sit at 44.8 units per ton and Clan Ferro is at 48 units per ton and would therefore apply to more mechs and it should be according to geometry needs.)
Another example, the HBK-4G can mount up to 338 armor currently, and has a quirk that gives it 18 armor to the Hunch. If we increase the max by 2.5x that takes us to 423 rounded up so, the mech has a difference of 85 - 18 = 67 additional units of armor to distribute onto the mech.
And I too would multiply Internal Structure by an additional value of 50% from current base stats minus quirk boosts, since the idea is to raise base values and remove armor and structure quirks with having their boosts rolled into the base stats.
The next factor is to increase the torso speeds and increase torso pitch so that they can track faster and also be able to fire at lower and higher angles. That would be a big help for what they can currently pack, aside from hardpoint inflation.
And specifically, with the 5V itself, what if it was one of the few mechs that could mount a TAG (and on it's own unique hardpoint and be finally infrared) be able to call strikes and hold locks for LRMs? If LRMs see improvements and strikes are restricted in this way, the 5V could have a new role with existing gameplay elements.