considering the important dynastic links between the Plantagenets and the Welfs in this period, I can see the latter possibly supporting the candidacy of Richard of Cornwall and his subsequent rule in the HRE ( although the problems he had in Otl would need to be resolved )
technically he had been officially recognized as the " only " Rex Romanorun around 1265s, furthermore the support from the Palatinate, Cologne and Mainz, and the coronation in Aachen, helped him in the dispute with Alfonso X of Castile ( although in fact Bohemia always remained ambiguous as to whether or not to recognize one of the two contenders, deciding several times not to take sides, so if Richard really wants to aspire to something more, he would need to convince Ottokar II to support him ) , but his real obstacle is that he did not possess a real personal state property of a fair size within the Reich ( hence his marriage to Beatrix of Falkenburg, with the aim of increasing his influence in the HRE, but unfortunately for him he spent little time in Germany and did not have the resources to impose itself on the princes and finally there is the problem of being recognized by the Pope, so it would be necessary to be able to organize a Romzung ( as it is called in German, the descent into Italy of the aspiring Emperor to be crowned in Rome ) and also be able to extricate oneself from intra-city conflicts between Guelphs and Ghibellines ) without forgetting that Richard was also distracted by the problems that were happening in England, in fact several times you had to give up continuing his policy in HRE to assist his brother against the barons
I'm not saying that it is impossible for Richard to be officially recognized as an HRE, but he would need conditions more favorable to him ( such as being able to use the imperial ban on a political opponent, in order to gain a fiefdom in the Reich, to be used as an initial basis for building his power in the Empire , being able to spend longer periods of time in Germany than Otl or at least visit it several times, get Bohemia on his side ( which was the main local power ), rebuild a central authority in the kingdom from scratch ( which required Rudolf I, at least 2 decades of conflicts and negotiations, which prevented him from being able to go to Italy with relative safety ) it is not even a given that he will then be able to have his son elected/confirmed as his successor ( it is probable that Richard is unicum , given that in this period the princes were tremendously suspicious of any would-be ruler who managed to gain any semblance of real power ) but at least in the event that he actually succeeds in having himself crowned Emperor, there is the possibility of political chaos within the HRE, addressed 30 years ahead of OTL ) even if he would actually have a small advantage on his side, especially if he were to maintain the support of the Palatinate, Mainz, Cologne and have Bohemia support him, i.e. the electoral college is not yet fully formalized / ossified, so he could exploit this detail to create new allies, promising an expansion of the college ( after all there is the precedent of Bohemia, which was a brand new addition to the group ) furthermore, to obtain the role of Saxony, the two dynastic branches created after the division of the duchy of Saxony by Frederick I are currently in open competition, therefore implementing a policy aimed at courting them to gain their support would not be a bad idea ( particularly considering that Albert I died in 1260, and then his sons immediately began to clash over the inheritance ) it certainly wouldn't be comparable to the result of getting their own relative on the imperial throne, but it would still be close enough, also not having a solid base within the Reich, Richard would be more available / malleable to support the Welf claims in the HRE