Retention Bonus Expectation?

I'm going to try to not dox myself as this is a fairly specific scenario I'm going to outline here, I'll try to give enough details to get helpful advice without someone I know IRL figuring out who this is about.

I work in a $1-5B revenue SaaS PE backed company. Someone on my team who was a more financial systems tech side lead was let go this month. They were a Director with a TC was in the ~220k range who was also burning my total burdened comp per month in consulting fees to support their efforts, call it 35k a month for simplicity sake between their comp and the spend they incurred.

We are in the middle of implementation of Oracle from Adaptive with the idea it will make us more attractive for IPO, I'm not sure that is the case, but that's the story I've been pitched as to why we are spending 12-20M on this implementation and license cost. There are two employees who know our current system really well, I am one of them.

I'm currently a manager and I feel a good bit underpaid for YOE and expertise (board reporting + systems admin) at 135k. Notably this is a remote role. I took this gig because my previous company had layoffs unexpectadly and I lost about 20k in TC.

1. What would you expect in this scenario as a "retention plan" to not look for jobs elsewhere?

2. Would it be unreasonable to counter with "retention and title + comp of the Director role that is now vacant who I will be doing the work of between now and then upon completion of the retention period." And also asking them to give a similar offer to at least bump the other key employee up in a similar manner?

It is important to note that this is a this is a very interesting situation where I and the other key employee happen to be good friends outside of work, and I actually got them the role (where they have excelled). It feels like anything but title and comp bumps are not true retention.

My thought was... wait to see what the retention offer is first, then counter offer accordingly with some severance guarantee if I'm laid off shortly after said retention period. It feels aggressive, but this is truly a unique scenario where I know I have options, I know (at 14 YOE) I am underpaid. And I and the other key employee are well liked by all.

Also the guy who had my current role previously left here for a similar jump, 137->180+10% as a Director. I know that because I actually worked where he does now before this role and was privy to comp packages. That has been my plan all along if there was no plans to promote me and I know this is the other key's plans too.

I hope I don't come off as cocky. But if anyone is good at telling me what I'm missing / the flaws in my plan, it'll be you good people of r/fpanda.

I've never been in this situation and honestly didn't forsee being in a position where I was valued enough anyone wanted to pay me to not bail mid-job. But when there are literally over $1m a month being spent on Oracle implementation prep... and we just fired the guy who was the more tech side (while I'm a more 70/30 fp&a / tech hybrid) - in their shoes I'd be really scared for both monthly timely reporting and IPO readiness if someone like me left.

Advice - if you actually made it through my scrambled ramble?

TL/DR: Key Employee being offered retention bonus, how much is enough and should I counter or is that even a thing? I'm in uncharted territory here. 14 YOE, $135k TC, FP&A Manager of consolidated board reporting, budget building and financial systems administration. Yes it's really all 3.