Maybe I missed it in the description or I interpreted the mod wrong, but for some reason my solar panels and accumulators get a 40% bonus productivity BASELINE.

Which is to say, instead of 60kw they produce 84kw (with no upgrades researched). This bonus also seems to scale with whatever I set the multiplier in the options. When I for example turn the multiplier up from 1 to 3, the baseline panels produce over 130kw w/o any upgrade techs researched.
The same happens with accumulators - even with a mult of 1, they now hold 7MJ instead of 5 MJ. All of this is not reflected in the tooltips btw, but I guess that's because of how the mod works (which is fine, I am just confused about the increase coming out of nowhere).

The tech increases normally with whatever I set the multiplier, that seems to work fine.

To be clear, this only affects entities from this mod, entities that have not yet been replaced by Solar Productivity have the normal values they should have e.g. 60kw for panels and 5MJ for accus.
Is this intended? If not there might be some weird interaction with another mod.

This problem got "fixed" as soon as I researched the first upgrade tech - all entities were updated and now have the correct values (15% increase at 1 mult).

Weird.

Seems to work correctly to me. Solar panels and accumulator get a bonus production directly in the entity tooltip. Mayve you already researched some productivity levels before, but every time a new solar productivity tech is researched, all entities get updated once again :)

Well, it was on a fresh save so I know for a fact I had no tech researched yet - I only happened to spot it in the first place because not all placed panels/accus were switched with the new entities from your mod, which was very obvious to spot in the power production overview. I would say about 15% of all panels/accus got converted on placement and /sp-update did not change that fact.

But, as you said, as soon as I did research your first tech the update was triggered, all entities were replaced and the bonus was then correctly applied.

Regarding the tooltip, what I mean to say is the crafting tooltip shows the base entity, which does not show SP bonuses, but when there is an SP entity already placed (a solar panel for example) the tooltip does show the bonus being applied - the issue was just that there already was a bonus despite no research on it ^^

It's a bit janky (not blaming you on the jankiness in this case :D I do run a bunch of mods) but seeing as it does get resolved with the first productivity research it's not a major issue. As an aside, from the tooltip SP entities don't get touched by any other mod, so it's probably something weird with the trigger firing.
Thanks for taking your time to reply tho :)

Thinking about it, let me turn that on it's head - is your mod supposed to replace panels/accus on placement before the first productivity update? Because that is where it was kinda jank on my end, with some entities being from SP but most being the "vanilla" base entity.