The problem will be that for owner occupiers your house will be the last to be considered.
A previously rented house should be just as good for an owner occupier. The downside is that you can't rent it for at least 2 years, which most won't want to do anyway. I think the loss of BTL buyers isn't likely to have a huge effect on the price bid.
Ofc, a previously rented house might have a lot of wear and tear.
I would not think there are many BTL investors active in the sales market now
Sure

.
This is why vacant possession is key when selling. You should get (almost) as much as you would for an owner occupied house.
There are now 3 types of house
Owner occupied (no rent history)
These houses will be preferred by BTL buyers. These houses effectively has no rental history and thus can be rented out at market rate. It would then be locked into the rent control 2% per year rules.
Owner occupiers can still bid ofc, but they are ideal for BTL. There are probably enough of these houses to satisfy all BTL buyers, so they will focus exclusive on these houses.
Rented recently (vacant possession)
An owner occupier will be happy with these houses, since they aren't planning to rent them out anyway. The previous rent is irrelevant and after 2 years of living in the house, it goes away anyway. That should be fine for most owner occupier buyers.
BTL investors will avoid these houses. It means the initial rent setting will need accurate information that the buyer won't have and the seller has no incentive to provide. This just adds hassle and extra risk. Better to buy from an owner occupier (or not buy at all).
Rented (tenants still in situ)
An owner occupier won't want these houses since they can't move in immediately. They will have to go through the whole process of evicting the tenants. They will have the right to evict for landlord move-in though, but it is complex and time consuming.
BTL investors will strongly avoid these houses, since they likely would have long term tenants with below market rent in them. If the tenants were amenable to leaving, the seller would have obtained vacant possession already.
In both cases, it might be worth buying if there is a sufficient discount on the price.
An owner occupier who isn't planning to move in to quickly might decide it is worth it for the discount. This is very risky though.
There is a potential arbitrage opportunity. It could be profitable for someone to buy these houses at a discount, evict the tenants and then sell with vacant possession at full price. As long as they make sure to remain small landlords, they could evict for landlord usage. Given the delays, it is not clear if this would be feasible and there is a lot of risk.