B2B Sales Driven S(P)aaS for hardware

I have started to build a SaaS tool in the category of B2B Sales Driven S(P)aaS for hardware. In short, what it exactly means is this:

Hardware management platform designed specifically for the electronics device industry. It enables companies to track and manage hardware development in the cloud, streamline sales&billing with niche-specific CRM tools, and create integrations with outside systems to bring your customers an even bigger range of services.

We started with something completely different, and then while trying to meet potential customers, they started to ask if it's possible to have one platform to reap all the benefits from sales and hardware development.

We are currently in the development phase of the MVP and waiting for public funding which we were granted for the R&D part of the project. I also have to mention that we have 2 clients which will be using the MVP for a small subscription fee as our early adopters.

While in the development phase my goal is to do the real product-market fit, create the branding around the company/tool, and of course, check if the tool is really scalable.

Here are my main concerns and ideas with which I need help:
I wanted to aggregate at least 3000-4000 potential leads from multiple sources and start engaging with them. What I'm unsure about is should I engage with them as If I'm offering a demo where I "interview" them and should I offer Join Beta with some sort of discount. Is there any other better way? Or should I just interview them and ask for a feedback, and engage them later after?
Our development will last until the end of the year, possibly early 2023, and I'm scared if I contact them now that they will fly away.

From what I've seen so far for User persona analysis is that most of the owners in the hardware sector (industrial iot, agriculture, surveillance..) aren't really using any kind of platforms other than Linkedin, and they are not eager to go through the website and search/investigate. So we would need to rely on Linkedin posts and articles directly posted there, niche-specific newspapers and fairs/shows. But I still need to prove this to myself based on the larger number.